Importing a 21,5-gig database dump in MySQL (MariaDB), takes forever and gives quite more actual data amount on disk than the dump weighs in.
Indices, I suppose, but... Fuck.
MySQL is very much a product of its time. It was brilliant in the 90s and 00s and even early 10s, but now it SUCKS ASS. Disaster recovery is nigh impossible.
Yeah, you kinda can backup physical database files. But it will work with either MyISAM, or when you backup everything all at once, not so much with individual InnoDB databases.