Most people quit playing a given sport seriously because they have to choose between that and making money.
I swam for 4 years in college and I only know 1 person who had a career ending shoulder injury, and that one because it was misdiagnosed for a year.
OTOH everyone I know who played football at any level has at least a minor nagging injury.
I suppose it is reflected in 'old timer beer leagues'. There are a few 50 year old guys on my team right now, and they can play fine they are just slower. Sames holds for baseball.
Even though football isn't that popular here - most of the guys I know that did play with hopes of making it big in the US college system ended up injured.
I read somewhere that a lot of baseball players will just call a cab if they have to walk more than a block or two because their ankles are so shot. Not sure if this is true or not though.