I got rid of both and my system is much better for it. The only thing I still use that is distributed in such a format is AppImage, and mainly because it has never given me trouble.
Snap is mostly limited to Ubuntu and has to run as a daemon.
Flatpak gives me cross-platform/cross-distro software directly/certified by the project or company that has additional security sandboxing and doesn't open up potential security issues.
I don't have to wait for a distro package, and yet there are no system integration concerns.
It also works great for atomic distros (SilverBlue, etc)
I have to say that I really do not understand the point of comments like this.
The reality of user-facing Linux is this:
Most of it is Android. It sells billions of units per year.
Of the rest, something like 90% is ChromeOS. That recruits 2-3 hundred million new hardware sales a year, which is roughly 10x as many users annually as the entire history of the Linux distro world. ChromeBooks sell more than desktop PCs and more than Macs by value although Macs cost at least 5x as much.
But of the remaining, oh let's be generous and say 10% of Linux users, most is Ubuntu.
Debian-based distros are 2/3 to 3/4 of all traceable measurable Linux usage, and 2/3 of Debian-family use is Ubuntu.
Red Hat and its fantastic valuation is like 1% of the Linux world.
So what you are saying is "only the Linux mainstream uses snap, and all the weird little hacker/hobbyist distros that have like ten users don't use it."
This might be the incentive I need to finally purge snap.