I had been designing games under the original OGL since its release in 2000, I had honestly thought that it was the best system (3e) for a long time. Designing for 5e was much easier, but it also had a lot of expectations that you are supposed to follow (formatting, "natural language," and design traps like class archetypes).
Stepping away from dnd altogether, and making my own new game system has been truly liberating. My decades of experience allow me to custom tailor my game to the kinds of games I want to run, rather than what has become the norm.
Dnd has become an overarching standard that has kept designers from branching out and finding new forms of innovation within the field of game design. There are still countless methods and mechanics that haven't been discovered yet because we are comfortable living inside the dnd box.
Maybe its time to step outside the box.
“Without deviation from the norm, progress is not. possible.” – Frank Zappa.