Why can't sports teams adapt?

Boy, if things don't change drastically soon I know more than a few who'll go ballistic when football season gets cancelled.  They'll be riots for sure.

I was just listening to a couple of male broadcasters lamenting how Covid-19 might affect the basketball and hockey seasons, which made me wonder:

Can't they ALL begin playing again once things open up?  Is there some law I don't know about that says baseball can only be played from March to October or hockey October to April?  (I had to look those up.)  Instead of fans suffering a complete year of withdrawals waiting for the next season, why not start playing once it's SAFE FOR ALL?  The players are still getting paid (aren't they?), didn't things turn out nicely for Tom Brady.  Sometimes we just get lucky.

And why couldn't the same apply for schools?  Wouldn't it be nice for work-at-home parents to have some time alone when the weather's great?  What's wrong with kids having summer vacation in the winter?  Or spring?

Why not?