i watch cs 15 hours per day and when i was playing cs 3 years ago i was constantly dropping 40 bombs on global with pistol only, faceit was unplayable to me back then because i had over 200+ ping to most of their servers
overwatch is about 3 times deeper than csgo:
You have an infinite amout of strats and hero combinations especially with weekly hero locks being introduced, you have more maps than cs will ever have (30 year old game btw).
About 4 times harder to get kills, players on ladder are way more developed than disabled degenerates you have in cs matchmaking, not even talking about csgo esports vs overwatch league/contenders.
No movement acceleration, over 30 hitboxes, speedboost aura, you change your movement direction as soon as you press button unlike in cs). You can be unhittable. A lot of shields in some metas, maps have lots of natural cover. Meanwhile in cs you have free kills standing still in open areas, also cs is probably the easiest game when it comes to trying to headshot someone. And many movement abilities, good luck 360ing your mouse 3 times in a row within 1 second and then trying to readjust your aim against no hitbox crouchspam hero that will oneclip you within 0.2 milliseconds.
There are counterplays to abilities and ultimates, while aiming you also thing about who might flank you and think about 20 abilities on each player and 12 ultimates each team.
The only "hard" part about csgo is playing against disabled clowns like zywho abusing telescope chest oneshot gun, but snipers in overwatch are way more dangerous yet 3 times harder to be good with.
EVEN SIEGE > CSGO in terms of skill and game depth.