The only advantage most of these parties have is not having been in a position of power to demonstrate they are at least as incompetent as other parties that have, if not significantly more so.
Germany's immigration policy over the last decade wasn't an ooopsie though but a deliberate choice by the establishment.
The PVV in The Netherlands twice (once as a coalition supporter, once as part of a coalition). Both times were a disaster. People just go to the next populist right-wing party (e.g. FvD, which is more extreme right than the PVV, pretty similar to the AfD) and then after a few years they come back.
I guess the upside is that in countries with a multi-party system (happens more frequently without first-past-the-post), they virtually always have to form a coalition, which typically ends up in infighting within a party or between parties. E.g. in The Netherlands you typically need four parties nowadays to form a coalition.