Here’s a head scratcher for you. I have tried installing Avast Free 22.12 without Web Shield and Mail Shield on some 17years-old old hardware. I modified the Avast default settings to my usual liking, ran the rigmarole of a Smart Scan and then shutdown the system. On restarting, I went to the Avast UI and installed Web Shield and Mail Shield. The result was a sparkly performing Windows 10 22H2 system (Toshiba Satellite Pro P200, 1.8GHz Core Duo processor and 4GB RAM) which had previously performed in a very unsparkly fashion.
I previously posted a comment (in about May 2022) about this ancient but nice Toshiba laptop performing acceptably with Avast Free 22.4 and then very sluggishly with Avast 22.5 and later. It is an understatement to say that I was delighted with the result of this tweak. It also runs quicker than when I was using Windows Defender (which was quicker than Avast without the tweaked installation). I have found the same benefit with a similarly ancient system running Windows 7 Ultimate x64.