I’ve got two complete sets of 4 tire covers. I’ve never used any of them. I got 10 years out of my last set of tires at which point I changed them; not because there was any signs of any need for new ones, but because I was going on an especially long road trip and I felt i shouldn’t tempt my luck.
That being said, if you have tire covers and want to put them on - do so; there is nothing wrong with that option. In my particular case, I have them and don’t bother using them - nothing has seemingly been wrong with that option either. I would guess that it all would depend on your particular circumstances. Some may need them and some may not. I may live in a place where the sun is far less of a damaging factor than where you live.