My question is: shall I bang my head more on that wall and finally manage to install MySQL (and repeat this procedure once a year when the distro makes a version upgrade) or go with the flow of MariaDB?

When I migrated from MySQL to MariaDB I was unsure...but, in hindsight it was good move.

However, if you use temporal tables, spatial data types or you run DDL from Perl, you will have to make quite a few changes to your SQL. If you are not using those then you will probably find the migration quite painless.

EDIT - added missing 'not'...