Extending the life of a razor blade sounds nice, but cutting hair perpendicular to the blade means shaving against the grain, does it not? I don’t want to handle the pain of doing that on the first or second pass while the hair is still long enough (like a couple of millimeters or longer, which cannot be trimmed using a trimmer and needs a blade). But shaving against the grain gives the smoothest skin texture (at the risk of causing ingrown hair, which for me is quite rare).
What I’m saying is that I’d rather the blades dull and need replacement sooner than put up with the burn and pain caused by shaving against the grain from the get go. A few passes with the grain and perpendicular to the grain (sideways) helps the “against the grain pass” be less painful and provide a smoother result.
I’d still love a blade that lasts longer though.