It’s not the ideal solution, but it is approachable and understandable for technically averse users. I think it’s good to have, but I only used it for one package, and that was as a separate Steam install that included an old version of glibc that was used in a particular game’s (Squad) anti-cheat until it updated it.
It’s good for a stable platform, but each package needs it’s own set of everything, which can be good (like the Steam example above having its own version of glibc instead of using the shared version on my system), it’s a lot of bloat. I’m not using it unless I require it for some reason, but again it’s nice to have around.
I don’t think Flatpak is going to be compatible with Steam anyway in the long-term because layering container solutions doesn’t generally work very well, and Steam is going to want to use its own solution for better control over the libraries each game uses. Earlier versions used library redirection and some still do.
