You do bring up some good points but let me clarify the points I'm trying to make:
You keep saying this, but the trend of the data shows the opposite is true and on multiple factors.
What was the highest charging amps for Tesla cars through the years?
2012 through the first few years, it was 80A.
Then, with the X in 2015 and S redesign to match, it was down to 72A.
Then with the 3 in 2018 and later the other cars redesign to match, it was down even further, to 48A.
That's not a trend going upward.
I'm almost certain that home charging with a wall charger was never at 80A... Perhaps what you are referring to is the car's max ability/rate of power "ingestion" (for the lack of a better term). Or perhaps I'm wrong - I don't have the data in front of me. Please correct me if I'm misunderstanding here.
In any case, my point in bringing this bit up was simply that we don't know what the future holds. If it only costs a few dollars, why not future proof as much as possible?
And you keep saying the time it takes to fully charge your battery. As cars go from 200 miles to 300 miles to 400+ miles of capacity, why does your workplace magically become 200, 300, or 400 miles farther from your house? It doesn't. You don't fully fill your battery from 0% to 100% every night. You drive however much you drive each day, and increasing range of the cars doesn't change that. As a matter of fact, more capacity in the car means you have more range leftover every day, meaning less need for faster charging.
You're missing my point here - I'm not suggesting everyone charges from 0-100% every night, nor am I suggesting distance needs will increase over time. Regardless of the capacity of the vehicle, for any given trip, there is a minimum amount of charge required to get you from A to B. If you are below that minimum you will need to charge. The faster your charge, the quicker you can reach that minimum. There are plenty of real-world cases where you need to reach that minimum on short notice, so having the ability to charge faster can only help.
Saying that the car has more capacity means you have more leftover range every day is in and of itself true - I won't argue against that. But if you regularly need to use more than 50% of a car's max capacity in a single day, then it is not a viable solution to the problem on its own. Yes it will help as you need to charge less the next day, but in this case, you will always need to charge the next day regardless. Yes, it lessens the need for faster charging, but does not eliminate it. Having the ability to charge faster only helps - why restrict yourself when it is likely to cost you a small % of the total install cost to ensure your permanently installed infrastructure is not the bottleneck.
And speaking of ever increasing capabilities of the cars, they improve in efficiency. So with the miles driven staying fairly constant, it is using up less energy for that distance as technology progresses, so it needs less energy refilled and slower charging speeds will be fine.
This is a good point, but you're speaking in terms of hypotheticals. In the same vein, who's to say a person does not switch jobs to a further location? Who's to say a person's life situation doesn't change and suddenly requires more constant, further trips?
And then to what degree will efficiency improve? If efficiency doubles in the next year, then yeah maybe you're right, no need, slower charging speeds will be fine. But let's go to the other extreme and say there's a 1% increase in efficiency in 10 years. Well, for an extra one-time fee of $50 you are giving yourself the option of having 20% faster charging speed over that 10 years you're waiting for efficiency to maybe improve. Don't hold me to the 20% figure. that's just a number I'm half pulling out of my arse. 60 amps vs 50 amps - the point is not the actual % but just illustrating that there is a perceivable immediate benefit. Just two extreme examples. Reality will fall somewhere in the middle. But the point of this was simply, yes, things will become more efficient and so all else held equal, fast charging will matter less. However it does not change the fact that there will always be a scenario where you need to reach a minimum level of charge in a minimum amount of time. Having the capacity for faster charging will never be a disadvantage when compared to not having it. The only trade-off is upfront cost. And in OP's situation, I can't imagine there is any scenario where the extra $50 will be an issue on a $1000 permanent install.
So on a per car basis, no, we will not need ever increasing recharging power, so I would not go with that reasoning. However, the proliferation of more EVs into the market does likely mean more households switching more vehicles over. So preparing to split charging onto a 2nd or 3rd EV would be a good justification for that. Switching vehicle type, from a sedan to a big inefficient EV truck would be another reason.
I absolutely agree with your last point here. Being ready for split charging for another vehicle is going to become a more likely scenario as we move into the near future. Whether you plan to buy another EV or not, pretty much all car companies are shifting a large portion of their strategies towards EVs. And at least one major manufacturer has committed to ONLY producing EVs in the near future.
Again, all of this is to simply illustrate that it is not foolish to prepare for future eventualities if the marginal cost to do so is extremely low. Even if battery capacity goes up, charging efficiency goes up, and charging throughput goes down, it will not completely eliminate the need for fast charging in certain circumstances. It might reduce it but not eliminate. So why condemn yourself now if/when those eventualities do crop up, when it would likely cost you a tiny % of total install costs to future proof to the current maximum?
As a bit of an admittedly facetious metaphor: I don't usually use my pinky toe, but if you threatened to chop it off unless I gave you $50, you'd be all the richer. I wouldn't go and chop it off just cause i don't need it. One day I might. So I'd rather have it. I like having my foot at max toe capacity, even if I don't use all the digits. (Don't analyze this, just trying to inject some humor here).