The standard may suck due to too few local dimming zones, but the "pathetic amount of brightness" is a hard "for you" kind of deal. It depends on your use case.
I use an LG OLED TV as a monitor for work (and a game here and there), 4k 120Hz and I'm more than happy with the brightness in HDR content. In fact, it's kind of just at the edge of being too bright for me... given the distance.
My complaint about HDR 400 was mostly with LCD monitors, not OLEDs. OLEDs may not get bright, but at least they get infinite contrast and perfect blacks.
That's a huge improvement compared to a lot of the garbage HDR 400 rated LCD monitors.
I use an LG OLED TV as a monitor for work (and a game here and there), 4k 120Hz and I'm more than happy with the brightness in HDR content. In fact, it's kind of just at the edge of being too bright for me... given the distance.