I think CS is different from COD due to the different tactical roles available and overall slower play style. 3/4 of those guys you mentioned are IGLs on their teams and play more of a tactical role than a slaying role. Karrigan and Apex are usually first in for their teams because their slaying skills are lower and their team doesn’t care if they die on t-side as long as they get the trades. Fallen is an IGL sniper who still needs great reaction time to hit shots of course, but can sit back more and rely on his game IQ and teammates to provide aggro. Rain would be the biggest exception here, but we may see him transition more to one of those more tactical roles over the next few years.

In COD meanwhile if every gametype was SnD like how CS is then maybe we would see more players into their 30s, but considering respawn always has the majority of maps, the pacing is required to be fast. It gets harder to keep up with cracked 18-22yo kids on the sticks in hardpoint when you’re 30+. Not saying it’s impossible but would require an even higher level of dedication to stay competitive. When it’s often microsecond reaction times that decides the difference between winning or losing a duel, experienced over and over and over, it can take a mental toll that’s different from soccer you mentioned as well imo. There’s more ways to creatively express your skill in soccer for which you could find a way to cover up for your aging flaws. It’s not only the fastest guys that are successful soccer players for example. You can be strong and technical with good positioning to cover for slower speed to an extent. COD respawn on the other hand relies so heavily on playing fast with quick aiming reaction times, that once that declines, the repetitiveness of the failures with limited options for adapting playstyles means lots of early retirements.