It should be noted tho that the easiness of "finding a way", and the difficulty of enforcing the law, varies widely between these.
For example - and I say this as someone pro-gun - gun control would likely be the easiest to enforce since it necessarily involves physical things, and not easily obtainable ones at that, at least if you want efficient guns. E.g. black powder is not hard to make, but good luck trying to make it work in anything semi-auto without constant jamming. Sure, there's an active "gun hacker" scene where people come up with designs that can be made at home with readily available tools etc, and it's great as a counterbalance to heavy-handed attempts to regulate... but there are no from-scratch designs that are even close to just about any semi-auto rifle on the market in terms of firepower or reliability (the non-from-scratch designs involve making the regulated parts of the firearm at home, and buying everything that can go over the counter; in US, the latter is everything except for one part).
OTOH if you ban encrypted messaging, how would you enforce that? It's hard to detect on the wire if the protocol is specifically designed to withstand such scrutiny, so you'd have to go after distribution of software. You could force Apple and Google to scrub their app stores, but then people can still install directly on everything other than iOS, and they'd just download it from foreign websites. So now you need some kind of a national firewall to detect and block that etc. It's not that any of that is impossible, but it's certainly much harder, and it would affect a lot more people overall, resulting in more pushback.
For example - and I say this as someone pro-gun - gun control would likely be the easiest to enforce since it necessarily involves physical things, and not easily obtainable ones at that, at least if you want efficient guns. E.g. black powder is not hard to make, but good luck trying to make it work in anything semi-auto without constant jamming. Sure, there's an active "gun hacker" scene where people come up with designs that can be made at home with readily available tools etc, and it's great as a counterbalance to heavy-handed attempts to regulate... but there are no from-scratch designs that are even close to just about any semi-auto rifle on the market in terms of firepower or reliability (the non-from-scratch designs involve making the regulated parts of the firearm at home, and buying everything that can go over the counter; in US, the latter is everything except for one part).
OTOH if you ban encrypted messaging, how would you enforce that? It's hard to detect on the wire if the protocol is specifically designed to withstand such scrutiny, so you'd have to go after distribution of software. You could force Apple and Google to scrub their app stores, but then people can still install directly on everything other than iOS, and they'd just download it from foreign websites. So now you need some kind of a national firewall to detect and block that etc. It's not that any of that is impossible, but it's certainly much harder, and it would affect a lot more people overall, resulting in more pushback.