What Apple does is very different because macOS apps are mostly written using Apple's frameworks and there isn't a heavy unpacking stage like appimages. In Linux the dev landscape is way more fragmented and that means most snap and flatpacks need to bring A LOT of libraries and a lot of dependencies leading to tons of duplication and a poor performance.
I'm very, very skeptical when it comes to saying that this container tech provides more security. It does in some ways but it also allows for applications to ship with vulnerable libraries for ever. With "native" packages applications are forced to update their code because vulnerable libraries will be replaced in the repositories with newer versions and apps need to follow or become unusable.