Yaarel
🇮🇱 🇺🇦 He-Mage
If an indy publishes content for 2014, I feel it is the responsibility of the indy to update it for 2024 (if the goal is to stay current).I think the biggest thing is that they wanted to maintain compatiblitly with 3rd party content, especially subclasses. When you change the numbers and levels of subclass features, it requires more effort to convert than just changing the first/second level to third.
Having written and converted a bunch of subclasses for 2024, A5E, and TOTV, I can see why they'd want to minimize that. There are already people hesitant to use old material with the new classes or insist that it's not backwards compatible enough as it is. I think they would have had a lot harder time getting people on board with the original, more substantial changes in the UA.
Standardizing subclass levels is better for the game.