On Thu, 13 Jun 2019 14:07:43 -0700 (PDT), Tom Kunich
wrote:

I wouldn't be against a BB of just sealed bearings except for the
reports of these causing the housing to wear and the bearings to pull
out with the removal of the cranks.

Viscount had those in their "Aerospace" frames. There was a slight
interference fit between the axle and the inner bearing race and you had
to thump it in a bit, supporting the far side bearing so it wasn't
driven out of the BB. To keep the axle from drifting in the bearings
over time, there was a circlip groove outside the bearings. The axles
tended to snap there, a bit of a problem when it happened while standing
on the pedals... personal experience there.

The appeal of simplicity was certainly the BB shell, two sealed
bearings, one axle. No adjustment per se. Every few years you could
pop the seals off and regrease the bearings. But the execution was
fatally flawed in that case.