Electric motors are far simpler and more durable than an ICE. The motors simply do not break. From a wear and tear standpoint, there is simply less to break on an EV. You don't need a complicated transmission. You don't need physical shafts connecting the power plant to the wheels. You don't need belts, chains, spark plugs, or an alternator. What is the durability issue that you think exists?
As to the original Tesla Roadsters,
1) yes, they still exist.
2) But it was a small run production Lotus modification last manufactured in 2012. Like 2,000 of them were sold worldwide. Why would expect to see them at all?
The primary limit on EV lifespan is the battery. Vehicles like the Leaf that didn't have active battery management systems struggled with lifetime battery issues. But that is a solved problem. Plenty of Model S's with the original battery are out there with over 200,000 miles on them.
Your stories of people throwing away a car at 6 years are almost certainly bullshit rumors designed to keep people afraid of change. While lemon vehicles certainly exist just as they do for ICE vehicles, the vast majority of vehicles don't have those issues. Unless of course you mean someone that simply traded in for a new vehicle at 6 years, then that is common for ICE vehicles too and has nothing to do with vehicle longevity and everything to do with consumer preference for new and shiny.