I have way too many of them. Always buy them on flea markets... Mainly Unior, some USAG, some Elora, some Stahlwille (branded Garant), some long forgotten brands... They hang on a rack, but I really rarely reach out for them. Though every couple years there is a rare case where they just work best. They also give a bit more leverage than an average combination wrench. Sometimes a ratchet or a socket is just too bulky, the offset wrench goes far to the side so it takes no space directly above the fastener, while a socket just has to go straight...
Back in the day, these were used by mechanics cause sockets and ratchets were more rare and more expensive. It's relatively straightforward to make a wrench, while socketry tools require more standardised parts that are harder to make and ratchets need mechanisms, and you can't use a socket on its own without some kind of a handle or a ratchet while the wrench is a "done deal"... You just drop forge the wrench, push a broach through the hole and have it heat treated and it's a perfectly usable tool.
Even when ratchets became more common in the 70's, mechanics around here would use these to do the final torque to "save" the more expensive tools from high torque failures (which, for many 70's ratchets that didn't survive until today, were an issue).
I was looking at some Protos, but they seem like overkill for a weekend mechanic like me. Stahlwille seems more reasonable if I decide to get any.
Makes it sound as if there's something wrong with Stahlwille

They're most famous for their offset box end wrenches, and they are on pair in quality to Proto or any other top brands, they may just be less overpriced (though still not cheap).