My opinion only, but I think games like Burnley-Liverpool where both teams are wearing very dark kits are a lot tougher than games like this. I'd much rather have a game with white vs gray or white vs yellow (think Argentina vs Brazil) than two teams in kits like royal blue vs black.
In the US, we had a minor bit of overreaction when many MLS teams came out with white alternate kits. There are a small number of teams in the league that don't have some sort of white kit. One of them is Seattle Sounders, who wear light green as a primary and black as a secondary. When they played at Portland (dark green as primary and white as secondary), both teams wore primary. You had dark green vs light green. I think all professional teams should have an all-white kit, even as a third kit, to guarantee there is never a situation where you have a situation like this.
I'm all in favor of kits that are primary and some sort of non-white secondary (i.e. Liverpool's black and teal alternate kit with their red primary), but having that all-white kit option can remove some potential issues.