have a read here
Pure and simple they are hard sell adverts from avast and we all get them especially as David said after a smart scan.
they want you to buy their cleaner, plenty of free ones out there or their vpn.
Even on a brand new laptop with only windows and avast loaded it said i had loads of critical issues and 10gb junk
windows 11 is 20-27gb in size so a lot of the suposed junk it found must be part of windows or just a hard sell from avast.
Avast does its job decent enough. David has been on the free version for years while i pay for premium since 2014 and i also get all the critical warnings on the paid version.