The instinct makes sense: if your hairline is pulling back, grow what's left longer to cover more ground. It feels logical. It doesn't work. Length draws the eye to the contrast between where the hair still grows thick and where it doesn't - it emphasizes the recession rather than softening it. The guys who look most at ease with a changing hairline are almost always the ones who went shorter, not longer.
The reason shorter works is proportion. A receding hairline changes the geometry of your head and face, and a cut that works with that shape - rather than trying to recreate the one you had at twenty - will look more intentional and more confident every time. Confidence in a haircut is mostly just cut meeting reality without a gap between them.
The strongest options start with the buzz cut, which works because it removes the contrast entirely. When everything is the same short length, the hairline becomes a much smaller part of the overall picture. Depending on how far back the hairline sits, a tight buzz can look genuinely excellent - angular, clean, low-maintenance.
A crop - short on the sides with a little texture on top - works well if the hairline hasn't moved dramatically. It keeps the top section short enough that the recession doesn't create an island of hair, but long enough to have something to style. A mid or high fade on the sides helps here too: it pulls visual weight upward and balances the proportions in a way that a taper alone won't.
For some guys, the honest answer is just to shave it. A fully shaved head is a legitimate style choice, not a surrender, and it's often the cleanest outcome when the hairline has moved significantly.
What doesn't work: the combover, growing the crown long to pull forward, or any style built around hiding rather than managing. Hair has a way of moving throughout the day, and anything designed to conceal has to stay perfect to work - which it never does.
The best haircut for a receding hairline is the one that doesn't pretend it isn't there.