What they were producing 8 years ago and what they produce nowadays is an order of magnitude different. It’s like comparing your PC from 8 years ago to today’s PCs.
The cars themselves have more range and charge faster, but its not an order of magnitude. Maybe charge times on a road trip have dropped by ~50%.
Service has generally gotten worse as well, as the company has really struggled to scale. They've added a lot of mobile service and service centers, but they still can't keep up with the pace of growth. Good thing is that most of the newer cars aren't needing service much, but when they do it can be problematic.
The parent isn't suggesting looking at the ratio of happy and sad posters, which would definitely be selection bias, they are saying look at the rate and severity of complaints on it's own.
Of course there are defects, at that volume that would be expected.
Parent didn't say anything about rates.