I have a 10-year-old LG TV that runs webOS 3. The first update slowed it down - not that it was particularly fast to begin with - and every subsequent update made it even slower. It also constantly nags you to update the firmware. You can’t just refuse once; every time you turn on the TV, it asks you again. I won’t make the same mistake the next time I go shopping for a TV.

Forgot to mention - there were no improvements whatsoever in terms of functionality.