Some things I’ve learnt on this.
Some frames are worse at getting water into the bb shell. Water can get in from the stays and the seat tube. It’s worth bunging these.
I’ve drilled my bb shells to let water out. Once in water sits against the bearings and does the damage.
The cheap deore bearings are not sealed on the inboard side (where water sits) and do not last in bad weather.
Xt bearings have lasted me better, on one bike that ate bearings after each wet ride I found some ceramic sealed bearings that went into the oe cups and lasted ages.
Preload is key, I killed a hope ceramic last week with too much preload from a crank which would not fully seat (i swear the instructions for no. Of spacers are incorrect).
Don’t hang your bike on its side after a wet ride (like I did on the underside of the roof) as water sits on the bb bearings.