I think it depends on what distro you're talking about. Corporate distros like RHEL and SLES are absolutely going that way. It takes a lot of effort to backport fixes, and the money's not there in desktop Linux to make it worth their while if containerization is a viable alternative. Red Hat's gotten rid of a bunch of graphical applications for RHEL 10 and stated that users can get them from Flathub as an alternative. I believe there was some consternation when CentOS Stream 10 launched without even a packaged web browser and the advice was to install Firefox from Flathub (there's a lot of use cases where that breaks stuff), but it appears they've walked that back and started providing Firefox as a traditional package.
However, less corporate distros that mostly just ship built upstream software as-is since they don't have to support it for long periods (think Arch, Fedora, Void, etc) don't have that problem, so I expect we'll continue seeing them use traditional packages.