Neither. The Flatpak is built by unpacking the contents of the snap, after which it's a completely normal Flatpak.
Snaps are just squashfs images with that package and its dependencies, so if the snap isn't doing something fancy like using patchelf or depending on content snaps, it makes a lot of sense that the snap would be extractable and usable for Flatpak. It's probably doable the other way around too, though as far as I know snapcraft doesn't have an official way to use a Flatpak as its source like Flatpak does with snaps.
Is that necessarily bad, though? I always felt that the infrastructure around snap, and not the underlying technology, was what people had problems with.
Also, this feels like an appropriate time to shill for Aegis instead of Authy. Or any foss 2FA solution, really.
I never liked the technology of snap. I'm pretty broke and technically could waste money on a new PC but I rather not. So all my laptops and PCs have been stuff I've found in the trash or on the 2nd hand market for under $100. Snap has always ran much slower on older systems that I use. And by much slower I mean MUCH slower. Flatpaks also run slower than native packaging but at least it's usable.
Mine wanted to be a way to say that after I discovered Ente Authenticator (the link I attached), which is another 2FA app that keeps an encrypted backup of your codes and lets you access them on multiple platforms and it's foss, I "almost forgot about Authy" since Ente Auth replaced it perfectly for my use case.
I thought that since is not a very famous project others could have found it useful
Spotify too lol. What's so bad about that? It's just a special source form, after it's packaged as flatpak, there are no ages-long startup times or Ubuntu-specific security