In reality I used Norton for some time then for the last two years or so KIS,, now I'm using Avast with which I will likely stay as I like it - I have given a few AV's a spin & other programs for fun / to to have a look at them then imaged back.
That is also the primary reason I use Bitdefender(ease of use) & there is at least one more reason: Protection capability.
It is an install and forget kind of software IMHO.
I have used KIS since 2006, then in 2010, I started using ESET Smart Security 4.2, then again decided to use Kaspersky Internet Security after few years of using Eset.
Then late 2020, we decided to use ESET again.
I don't change my software, including security software, often.