What with Google and now GPT, it's critical that your framework is well talked about on the internet. Otherwise searching "show me some code to do XYZ using the frankenframework" will come up empty and then it's game over for your framework.
That makes building your own framework even less of a good idea than it used to be.
OTOH, if you build a framework/library, you might be able to use AI to generate thousands of examples of using your framework/library, then publish those examples. If it's too difficult for the AI to generate correct examples, then that may be a sign of what parts would also be difficult for humans.
We may in fact see an explosion of new frameworks and libraries that use this strategy.
That makes building your own framework even less of a good idea than it used to be.