Ham is harder. Internet comes (mostly) through cables; those cables at some points are subject to the control of the government, and can be either technologically filtered or physically disrupted. (Satellite internet is clearly the exception.)

But ham radio is like satellite internet - it's hard to cut off. You can ban it, as you say, but then you have to actually enforce the ban - either by jamming, or by finding sites that are transmitting and cutting them off.

But even worse, I don't think the point of cutting off the internet is to keep news from Belarus from leaking out. I think the point is to keep outside ideas (like the idea that elections should be fair, and outrage when one isn't) from coming into Belarus. Well, a ham can sit and listen and broadcast nothing. It's hard to track that down to be able to enforce the ban on the listening station.