Also... if you're playing BF on PC with mouse and keyboard and you're losing to a bloke sat on his sofa, playing BF on a controller using his thumbs then aim assist is the least of your worries.
Controller Players have gone a little daft these days though I must admit, with the era of Fortnight and Warzone more often than not they have a Monitor Setup with Thumb-stick Extensions, all that jazz!
I noticed so many PC Players showing up in lobbies on MW3 as Controller Input but were clearly using XIM with M&KB + Aim Assist and all sorts of Anti Recoil Scripts on big LMG’s just beaming people!
Thankfully, unlike in COD, devices such as XIM don’t play anywhere near as nicely with Battlefield’s and hinder more than give an advantage.