That Relay rewrite was over 3 years ago though, and it’s been pretty stable since (the hooks API is coming “soon” but shouldn’t break compatibility). And there was an upgrade path, there was an intermediate compat version which let you incrementally upgrade.

The learning curve isn’t that really that steep, it’s just made artificially so by the poor docs. It’s unfortunate that the Relay team doesn’t really prioritise getting new users, because it’d motivate them to explain things better. But there’s not actually that much to learn, you can be up and running and productive with it pretty quickly.