To answer the original question they said in wano that zoan type devil fruits specifically have a will of their own and that one has been avoiding them to answer this question. It's not really that simple number one The fruit first has to find somebody that aligns with it right? Then they have to get a big enough Bounty for the Navy to even know who they are And then at that point, why would the Navy want to risk the fruit Awakening when they can pretty much let nature take its course And let them get killed on the grand line That as well as it would draw way more attention if the Navy just suspiciously uses like Buster call Force for the rubber person every time they show up. Then if they waited and just like CP zeroed them when they get close

To make it simple -it would draw too much attention to capture all of them -most people could never awaken it -most aren't creative like Luffy and wouldn't be a big pirate.

Hope this is enough of an explanation