Nintendo found the one angle they could legally attack Yuzu from and they took it. They couldn't with Ryujinx, because Nintendo's legal power did not cover Brazil or whatever.
So they got their best private investigators to find the guy irl and give him an "agreement" to delete fucking everything suddenly and without warning.
Either they gave him an offer he couldn't refuse (1 quadrillion dollars) or they gave him a plainly worded threat, you guess.
...And Switch Emulation was splintered and never heard from again.
NS2 emulation will never have the legs that Switch had, for a variety of reasons. But a big one I think is that the emulator authors are either sued or into financial slavery or they vanish into total anonymity after Nintendo tracks them down.