Open question re rules on DL play

It has bothered me for years, Why can’t our DL get off or around blocks?

I haven’t noticed swim move wild man efforts to get off blocks to penetrate, disrupt or sack.

Are there rules (penalties) that discourage wild, go for broke efforts to get into the backfield and wreak havoc?

Or is it scheme to “gap control” ?

Looking for insight from those with knowledge, versus opinion.