My 2019 Philips android tv got incredibly slow after years of updates. I didn’t notice it because it was so incremental but after some years the chromecast functionality started failing consistently. I did a factory reset, disconnected from the internet and added a Google TV dongle. TV is super fast again. Point of the story: it’s very nice to be able to buy a $ 50-100 dongle every 5 years and keep your old tv.
This is exactly the approach I've taken. Current TV is 14 years old and survived numerous house moves. Still as good as new.
Most usage is via a Chromecast Ultra. I have a Chromecast 4K with TV (i.e. newer device) but it was a backwards step from an experience perspective (covered by others elsewhere).
