My opinion is that of the two Postres is more “adult”. So if you want to"just wing it" MariaDB would work, but if you’re serious Postgres is a better choice. However Postgres also requires better understanding of you setup etc. So it’s a ROI game - what’s more important to your project, how complex your DB is, what are the requirements for availability, transaction security etc. There is no “better” or “worse” there’s “feasible” and “prohibitive” 😉