Deinstitutionalization certainly didn't go well in the US, although that's more Ken Kesey and Jack Nicholson's fault than Fanon's.
Which is the neoliberal nihilist "f-ck everything" reading of the message of said works that could only come about as policy in the post-Nixon era of mutual radicalization and irresponsibility rather than a compassionate and reform-minded one, and I say that as someone who has suffered heavily at the hands of mental health practitioners that haven't been given their due scrutiny. My own shrink reflexively defends such practices as "fair for their time" or whatever, which certainly doesn't inspire confidence. Deinstitutionalization as a cheap political alternative to proper reform is on the tier of Delaware Day as the work of a welfare state shirking its responsibility in all the harmful ways that it shouldn't rather than de-escalating its abuses responsibly and with an eye to maintaining some semblance of social fabric.