Seeing this thread develop just now,
I don't think the question is as dumb as some people make it to be, it's a valid enough question to ask considering how we've been playing in this fluid system with 3 players centrally with fantastic ball control (Not kevin unfortunately).
I can see some arguments, Cancelo is operating in the half space and providing "similar" kind of delivery here as Kevin, while letting Bernie play who has better ball control than Kevin in deeper spaces. The duo are justified in a sense as starters as they complement each other perfectly.
That being said... Kevin's overall ability to create chances at any position on the pitch is the BEST in the world, with Messi just about 2nd best.
The fact that Kevin can play False 9, LCM and RCM means that since we need rotation anyways, he can easily rotate in these spots for plenty of game time.
But if its about a knockout game or final in champions league... he starts over Bernie for me, he's just way too good at creating.
Kevin at RW isn't a real option to me, considering how wide we play our wingers and how we want them 1on1, that's not Kevin. If Bernie can increase his goal/assist rate in addition with what he's already doing, then the decision becomes way harder, and I seriously don't know who to pick, great problem to have mind you.