A case could be made not just against Avast, but against AVs in general. They can often allow for privilege escalation:
https://www.google.com/search?&q=antivirus+privilege+escalationOne of the drawbacks of Linux is probably its gaming and design capabilities. For those who're not aware of their privacy & security risk, the 'inconvenience' also provides some challenges. On top of that, news like this does not come into headline every often.
As far as gaming goes, nowadays with Lutris/Proton/DXVK/etc. most games, AAA games included, run fine. For design it's not as good but that depends on your needs.