Yes, its all about investment and money you get in industry. If you take soccer it differs where you play . Pro league athletes earn enough for 2 generation if invested well after retirement . Not so much again if you go tier down Jamie Vardy had to do part time with his career untill he clicked with Leicester city . There is more to it most athletes need to jnvest on fitness every day , no time with family and more commitment to yhe team , there is also threat of losing contract if you dont perform to expectation so they need to be A game all the time. Its same with every sport .