PyPy is still slow compared to actual fast languages. It's just fast compared to Python, and it achieves that speed by not being compatible with most of the Python ecosystem.
Seems like a lose-lose to me. (which is presumably why it never caught on)
What isn't compatible with PyPy? I can run large frameworks using pypy no problem. There certainly will be package that aren't compatible. But far and away most of the ecosystem is fully comaptible.
