Not if the ppa depends on a system library not available on your release. Then you need to go hunting for more ppas, until you eventually need to up/downgrade your entire system.
That's a perfectly manageable issue.
But don't claim snap's are the only solution to the problem of getting up-to-date software. That's not at all true. We've been solving this problem for far longer than Ubuntu has been around, and their approach is hardly a panacea. For example, it can and will result in additional memory and on-disk bloat as a consequence of duplicated dependencies across packages until de-duplication is implemented.
If only there was some existing solution for packaging and deploying software where you could declare dependencies between shared resources...
Well, that and the sandbox features, so that they can't interfere with the rest of the system.
Huh?
If a snap includes version 1.0.0 of libxyz, and another does the same, you have two copies. If a third snap comes along and uses version 1.0.0 libxyz, you now have three.
Snaps do not automatically de-duplicate today.
That means two copies of the library living on disk and in memory at run-time.
So, they've reinvented dependencies (though, to their credit, they gave them a different name), one of the very things snaps were intended to alleviate?
Look, don't get me wrong, snaps have some interesting advantages (sandboxing being the one major selling point, IMO). But, again, they're no panacea.
Just like docker, snaps make sense even if there is some duplication of the libraries. Other benefits outweigh the extra size.