As a Korean freelancer, I’ve spoken with former developers from Pearl Abyss. They officially work 10 to 7, but the relentless crunch culture drives most people out.

While the company is extremely proud of its proprietary engine, I was told it causes severe internal politics. The studio is heavily biased toward the engineers who built the engine. Another huge downside is the lack of documentation—you can't just Google your bugs. (Granted, this was the situation two years ago).

The CEO is famously known in Korea for prioritizing developers while devaluing writers and planners. However, even within that developer-first environment, the proprietary engine has birthed a clear internal hierarchy among the programmers

Companies I remember: CD Project RED, but they are now switching their newest game to Unreal Engine.

id Software, the new Doom series uses highly performant engine (as if there was some legacy there for that).

The main point of using a 3rd-party engine like Unity or UE is not to buy technical excellence, but to get a 'good enough' asset pipeline, authoring tools and engine runtime cheaper than building and nurturing your own inhouse engine and tools team ... especially when the best programmers on those teams are then poached by Epic or Unity anyway ;)

Crimson Desert's engine is heavily derived from Black Desert's engine (called BlackSpace Engine) so it wasn't really from the ground up, but your point still stands.