In California, you can expect a wait at most SC's during normal driving hours, and on long weekends, it's been HOURS to plug in at some SC's.
Lets keep it 100 here. That's simply not true.
1. There are some CA superchargers that are known to often have a wait, but most of them are in Tesla dense areas where its more likely that locals are filling the queue, and most of those chargers are NOT required for travel between cities.
2. There are no doubt some intercity CA superchargers that can sometimes fill up and even have short waits during peak weekend travel hours.
3. There is ONE incident of massive wait times (Tejongate) that often gets cited as proof that the sky is falling. That problem was completely solved by opening the 10 stall Buttonwillow charger, 40 miles up the road.
I frequently drive what is no doubt the busiest mid-haul Tesla route in the country (Bay Area<-->Socal). I have NEVER experienced a wait at ANY charger along the route (except Burbank, and I knew that was coming...), and that includes president's, memorial, and independence day weekends this year. To be clear, that's not presented as a [false] positive that waits are non-existent, its countering your quoted statement above.
This is only going to get worse as more MX and M3's are built... even with Tesla increasing the number of SC's.
Its too early to make that call based on understanding of today's technology.
1. We have no idea what supercharging looks like on the M3, or how many people will be involved
2. We have no idea what the SC network buildout
really looks like, especially beyond the "doubling" statement made at the M3 reveal
3. Supercharger cabinets will continue to be upgraded--the latest is 145kw--thus decreasing the impact of pairing events
4. Battery capacity will increase over time, increasing range and thus reducing the per-charge kwh demand
5. Battery capacity will increase over time, increasing charge power/taper and reducing the charge time at each stop
6. Battery cost will decrease over time, allowing more people to afford 'bigger' batteries, decreasing kwh/charge
7. Vehicle efficiency will increase over time, increasing range and reducing kwh/charge
Also consider, many SC's don't charge as fast as they're suppose to. My wife was plugged in for 15 minutes the other day before she realized she was charging at 70A!! She was able to move to another charger, but that's not always the case.
And this is most often due to pedestal pairing. Its occasionally a hardware issue or heat/demand related throttling (or a cold battery), but quite frankly, if an owner doesn't cite a confirmation from Tesla that there's a problem, I side with the odds that the owner just doesn't understand the nuances of supercharger pairing.