For the best part of twenty years, I have from time to time tried alternatives to Avast. This time it was Kaspersky Security Cloud free. I turned to it because I have an old Toshiba Satellite Pro P200 laptop which has a superb display screen and runs Windows 10 21H2 passably. Kaspersky has a repution for being light on resources and so it seemed a good bet. Not a bit of it! Avast free showed it a clean pair of heels. With Avast, the Patch Tuesday updates took a little over half the time taken with Kaspersky.
It seems that I absolutely cannot find a decent alternative to Avast, popups, nags and all. C'est la vie I suppose.