Unlike grass, which you can only get with shears, you can use shears OR silk touch to get bushes, which i dont think is consistent. Grass gives seeds when you break with silk touch, but bushes give you bushes when you mine with silk touch. you can also plant bushes inside grass, which will just delete the grass without giving anything and replaces it with bush. Same can be done the other way.
Linked issues
Comments 2
Grass not dropping itself with silk touch is also intended behavior: see MC-166084.
Bushes being mineable with silk touch is an intended feature.
From the 25w07a changelog:
A Bush only drops when broken with Shears or a Silk Touch tool and is replaceable when building
Instead, grass not dropping itself with silk touch might be a valid consistency issue, since dry grass does drop with silk touch. (Could also be a feature request, we need Mojang’s confirmation)