[anonydsfsfs]

Wordpress was first released in 2003. There wasn't a database abstraction layer for PHP at the time (PDO was first released in 2005), so it was tightly coupled to MySQL.

[0x0]

And PDO isn't even a proper database abstraction layer, it's just a way to connect to various databases and issue prepared statements. You still have to write your own SQL queries and create table statements, which will most certainly not be portable.

[madeofpalk]

Fair. It's 2022 now. I figured in the 19 years since they would have done something like this.

[ceejayoz]

They’ve consistently prioritized backwards compatibility over pretty much anything else.