With a straight no matter the grind or brand or age or size you should be able to get the same exact perfect shave as you go from one to another. With a DE that's not the case. Each one has it's own potential and even with the same blade they are just different.

Some DE's I've used give really tame and (relatively) poor shaves while others rival a straight. Usually the more aggressive ones shave closer but there are exceptions.

With a straight I can usually get away with around 36 hours but that still means I have to shave every day. With a good DE it may be a few hours less but either way it's everyday shaving. Of course that's when I was working. Now retired I shave every other day.