If you’re cutting out parts, then you really only care about the linear time, and you can cut that faster with a 1/8" because you’re removing less material. Pockets could probably done a little faster with a 1/4", but not by much, because you’ll be going slower to have the same force. 1/4" bits can have the same absolute stepover, lower relative, which will speed things up.
IMO, the 1/8" is a great balance. I think there’s a reason why miter saw and table saws have a standard 1/8" kerf.
I don’t see breaking bits very often though (except in aluminum). They should get dull before breaking. The trick is deeper passes, slower, which will make the force of the work distributed across more of the bit, and make for longer lasting bits. The limit to that is if you are cutting a deep slot, you need to get the chips out quick.