Is the intel i9 1100KF still a decent upgrade from my i5

my motherboard only supports up to 11th gen (i don't know how to replace a motherboard and I'm too scared to)

i currently have a i5 11400 performance decent but in some CPU intensive games (like city skylines 2 ) it hits 95-98% usage

i can pick up a i9 1100KF for £120 (not including the money i could get from selling my i5)

is it still a worthwhile upgrade or am i being silly.