I have been using PlatformIO as of late, which has the option of selecting frameworks when the project is created. While that doesn't really solve the problem

I have been using PlatformIO as of late, which has the option of selecting frameworks when the project is created. While that doesn't really solve the problem of having a universal abstraction layer, it does ease the burden of installing frameworks since it handles that automatically and it provides a more consistent development environment. As for that universal abstraction layer, I doubt that it is practical. There is too much variation across features offered by MCUs. Ultimately some features would end up unsupported on some products unless every vendor decided to put their weight behind it (and agree upon how everything should be implemented).