Insider Fast Track Office
Agree fully with you there, I have not long ago brought new laptops for home and business use.
All had Windows 10 preinstalled, the first thing I did on all of them was get rid of 3rd party Antivirus, and use Windows Defender.
I may have invalidated the guarantee but at least I know, and have peace of mind that I wont have any trouble with 3rd party blocking or crashing the laptops.
They all update 2-3 times a day depending if a bug is found and they all scan and been clear up to now of any virus etc.
So for me NO 3rd Party at all