Alpine is a good system for the boot/main rootfs because it's rock solid and has the most recent kernel. When glibc is required or when you just want to access the repositories of other distros you can unshare and pivot_root into the respective rootfs (using bubblewrap). There is also flatpak (uses bubblewrap internally).

You can also go the extra mile and use bubblewrap to initialize the desired mount environment and then enter a sandbox from it using virtualization (/dev/kvm). Some VMM's such as muvm[1] even allow for hardware acceleration and performant Wayland pass-through.

[1] <https://github.com/AsahiLinux/muvm>

This project aims to do exactly what I described but defaults to Nix: <https://git.clan.lol/clan/munix>