Can you still write/use old style themes? It's been more than a decade for me, and although there where some WP-isms you had to know about ('the loop'), it was otherwise pretty straightforward using php as the templating language and (obviously) rendering html and styling through css. Standard stuff, that would let you dive in quickly. I'm sad to see that has changed.
Yes you can. I've been working with WP inhouse for a long time and I had no idea it had gotten as bad as in the OP article. I stay away from the gutenberg stuff and continue on with the "oldschool" stuff.
