A few days ago JWZ had a great take on where Mozilla is today: https://www.jwz.org/blog/2024/06/mozillas-original-sin/
My reading is that jwz thinks there was a possible future where DRM is dropped because it's as useless & impractical to enforce as cryptography export restrictions had been. Mozilla could have contributed to this future by not implementing DRM, but instead supported the outcome we got: DRM is ubiquitous, browsers that don't support it are disadvantaged significantly, and an anti-DRM streaming service (similar to GOG) no longer has any real advantage over DRM-enabled services.
It is possible that no DRM in Mozilla would have resulted in the same outcome we arrived at - Mozilla gave in, so we'll never know. But what does Mozilla even exist for if it's unwilling to stick to its principles?