Why anyone would willingly install a Norton product and leave it installed is a mystery to me. Yep, Norton bought Avast and its subsidiary Piriform back in 2021 so it would not surprise me if all kinds of Norton monitoring "features" have been added to ccleaner pro too. Same thing goes for Avira they bought in 2020
I do think some of the standalone Norton programs were great, but I use them and do not leave them installed. I mean I still resort to bootable Ghost to image things when other cloning software fails, even though many workarounds are required after Windows 7. I'd have no problem running ccleaner free and then uninstalling it (although I'd skip many of their registry cleaning suggestions) but not leaving it running and monitoring the system, no-way