So under condition if I disabled GPU acceleration, when I scroll down or up on the game's page in library or in "what's new" page it starts lagging just like when fps drops in game. I opened task manager and saw that when I scroll, only one logical processor being utilized on 100% at a time, each second "relocating" the load upon the other logical processor.

Specs are:
RTX 4060
Ryzen 5 5600x
16 RAM (2x8)

Nvidia drivers, chipset drivers are updated to newest versions. No viruses, any (too demanding) backgroud tasks or overclocks or additional programs (everything in bios stayed on default since the very installation).
I use GPU acceleration anyway, because of obviously better performance, but it's quite weird since my CPU isn't that old at all to have such lags, especially when I can run games like Helldivers 2 at (mostly) 60 fps on high. Perhaps it's problem of a steam itself?