I think I understand that addresses are hashed to compress massive coprimes.

I think I understand that transactions are hashed for the same compression motivation but also to keep the encrypted content more random thus more secure.

I can't figure out why blocks are hashed and can find no explicit motivation in the Satoshi paper, wiki, or here.

Are blocks hashed only to slow verification thus reward release rates?  If not, why?

Thank you so much in advance!