If you can aim assist snap as fast as someone can flick, it's fine. A lot of games account for this and it pisses off the "m+kb is the only good peripheral" crowd every time despite their constant insistance that controller is worse for everything. Even OG overwatch had competitive controller pros (e.g. Malik); map knowledge, good awareness and positioning, control of resource locations (or power weapon spawns in older fps) have always been skills that contribute to wins as much as aiming well, regardless of peripheral. The best peripheral is the one you're most comfortable competing with.