Another option that is still young (young as an Open Source project, but has a lot of historic development behind it) is O3DE (https://www.o3de.org/) I think this has a lot of potential if it gets enough attention and development.
I don't have much hope for it, I know several people that worked for amazon lumberyard (it's old name), that have quit because that organization is collapsing in on itself, losing engineers way faster than they can hire, and the engine is still buried under a mountain of tech debt inherited from Cryengine (that real Cryengine has resolved a long time ago)
One quit because the new render was so performance intensive, an rtx 2080 super was min spec for the lightest of scenes to achieve 60fps.
Another because he became the last engineer on his team after all the others quit and moved elsewhere at Amazon.
Even hoping open source saves it is unlikely, as it's only in name. The CI and infrastructure to meaningfully develop it open source does not exist.
As a final nail, the install process takes over two hours, which is just not competitive.
