why is CSGO so hard?

i used to play tf2 alot, i almost broke 1k hours, but when i went to csgo i was garbage (still not amazing but thats besides the point) because its so different, because to be good you need to learn spray patterns, site taking strategies and bomb planting strategies, smokes and flashes, tricks and other things to get your advantage over your opponent. i recently broke 1k hours on csgo and can say that if i were to go back to tf2, i would probably not do as well as i used to because i would end up playing like i play csgo