They do use Rubycon caps in PSUs though!
Not those Deer ones.
Decent ones use many brands. Hitachi, Sanyo, Panasonic, Nichicon, Rubycon are all good reputable Japanese brands.
There's so many out there particularly from China it's hard to follow any more.
In the old days I remember brands like Mallory, Cornell Dubiler (CDE), Sprague, etc. Of course then TVs and stereos had vacuum tubes or valves.
Nichicon and Rubycon were quite common in the 70s in strobe/flashguns made by GE and Honeywell. Those were fun to mess with. The four AA cell powered one I was familiar with had a 4700 μF 440WV main cap across its flashtube. That when shorted had the report of a good firecracker and would blow a hole in a beer can big enough to pass a pencil through. I got shocked by it before and it was a serious jolt indifferent from poking a finger in an electric socket! (on European power which is 220V!)