It's not just panel gaps. Trim falling off, poor part reliability, terrible paint quality, software issues, lack of real blind spot monitoring/auto-wipers/auto-beams/self parking... There's way more than just a few mm here and there that don't line up.
Not to mention - who knows what the reliability of battery and drivetrain components will be on the 3/Y. Though the 3 was initially released in 2017, really sales didn't take off until 2018 and 2019. So, we are viewing the reliability, which was already rated as 3rd worst in the industry, of cars that average 1-2 years old. Do you think in 5 years these cars are still going to be sitting solid? It's doubtful.
If any one of these manufacturers can put out a fun to drive, less than $100k car that is made with a premium feel, Tesla is going to be in trouble that segment. Seems like Rivian is on track to put out their truck in June. I don't expect it to be perfect or error-free, but it will be interesting to hear reviews.
All that said, I think the refreshed Model S will tell us all we need to know about what they have learned over the past 10 years or so. Given it's an all new interior, there has been significant changes to the battery pack, and likely other unannounced changes....Have they fixed the door handle issues, are the parts on the interior durable and rattle-free? Software is software and it'll never be perfect. We will find out in a couple of weeks.