if you have internet speed 2.5Gig from provider it should be okay, if you have something slower like 100mbit this is total overkill.

The best you can do if you want stable conection from pc is considering a wired connection rather than Wi-Fi, wifi has better numbers on paper, but reallity is diferent

If you have old router 3yrs+ it is probably what causes trouble, try to connect any device via cable that is connecting router to internet, idk if you have dynamic ip or you will need set ip from provider (it should be in contract), mesh system is good, but for big houses, if you have small apartment like 1000 square ft only one Wi-Fi router should be ideal. Idk what router you have, if is it old try replace it