you should stick with the need of your apps. If they need let’s say mariadb 10.5 then use the contrib. If they are fine with mariadb 5.5 then stick with it as migration will be easier to next SME.
For the moment we do not have any process to restore contrib provided database, so this implies a manual process to push the dump to your new db after migration, and decide in which one.
The hardware of your server could impose a limit ik the number of process running, but nowadays even if you only have a version only, systemd is designed to run multiple instance of the same service. so the model now is less one sever to serve all apps, but one mariadb server per app.
you do not have to move this way and this is mot the current direction we take, but this is to put in perspective.