I was a WP dev for 5-7 years before moving on to bigger and better things. It's easy to hate on the platform, for both justified and unjustified reasons.
As a writer, it's good not great. As a low code dev, it's the best because you can do 99% of what you need to do with no licensing costs. As a regular beginner dev it's a great platform to learn on. As an experienced dev it's just terrible to get anything done and too many people never graduate from it for larger build outs. Here's just a random list of hot takes I have (keep in mind I have not worked on the platform since Gutenberg got introduced, though I imagine much of the backend code hasn't changed)
- It's not an application framework, so stop treating it like one. It's good at blogging and decent for laying out web pages. If you need it to do other things, use Laravel or Grav or something
- File management is completely unmaintainable for anything more than a personal site. I've worked on some larger 2000+ page sites and it's nothing short of a nightmare.
- Post/page versioning is basic. There are plugins that do a much better job at accomplishing this, but it's time that it makes it into core. I'm talking about an actual publishing workflow with visual diffs and such.
- The backend API is atrocious. Using methods like get_post or the_content are great examples of why people hate PHP. Inconsistent naming, unclear usage, no namespacing, etc etc makes it really hard to read code. I'm a .NET dev so I'm probably a bit biased but with the amount going on under the hood, a service layer is necessary.
- Being able to rapidly prototype with themes and plugins is great and part of the dev experience, but unfortunately most projects never mature past the prototyping stage.
- The community surrounding WP is great, and Wordcamps are a great experience. I've given a couple of (admittedly bad) talks at WC Milwaukee and was surprised at the range of people that attend them.
- One of the talks I hosted was about how to use Xdebug with WP. Maybe things have changed, but I threw the talk together because _maybe_ 1% of devs I ever interacted with in the WP space asked if I had stepped through my code with a debugger. var_dump is a terrible crutch that PHP devs rely on way more than they should. I know things have improved with Docker compared to the days of Vagrant, but even at the time WP devs seemed to lag behind the rest of the industry in this regard.
- Last thing, I have terrible nightmares still about the database schema. Too many plugins/themes rely on post_meta and (whether you agree with them or not) I think WP needs a proper ORM.
Quick Edit: I will praise WP's for its plugin architecture with actions/filters. I've replicated this in our own .NET-based application and really love just being able to hook into places without dealing with nasty hierarchy structures.