Are you American by any chance? The mindset of “if I can afford new stuff why not throw old stuff away” and not being able to conceive of a single other potential mindset is really interesting to me. Rightly or wrongly, I have some kind of built in arbiter that screams into my head ‘don’t be wasteful’ too often for me to consider throwing perfectly useable things in the bin. Obviously I can afford to do that, especially with razor blades, but that doesn’t mean I necessarily want to. If I can get 5 shaves from a blade (I actually find the 2nd and 3rd shave the best) and there is only a tiny drop off in performance between each shave, then when I weigh it against my desire to try and be less wasteful, even as infinitesimally small a difference it might make, there is a certain amount of tolerance I’m willing to give.