Yes many good people say that. Eight billions worth of folks differ. Who is right?
If Norton et al could stop ransomware attacks then we wouldn't have any since any corporation would mandate them - if not then their insurers would. Or are El Reg's stories about incursions via Windows boxes fake?
And if they can get in to plant ransomware they can get in to do other stuff.
The issues with Norton et al is that not only do they slug performance but more dangerously give a false sense of security to the user. And we know from elsewhere what risk compensation can lead to. Defender is good and Norton et al need to be a whole lot better to overcome that.
Let's see independent objective evidence. I'm looking for double-blind studies to justify these mouth watering figures.