Is the PS5 worth it with a Full HD TV?

Hello.

I wanted to switch from the xbox one S to the Ps5 soon. However, I "only" have a LG full HD TV. My question is, would I buy a ps5 now, would the games be too pixelated or would they be of the same quality as my Xbox games? I want to get a ps5 mainly because of the new games.

No, probably even your monitor from your PC would currently be more suitable. Your TV probably only has 30-59 Hz, you can do it, you may not notice a difference if you are not used to anything better.