There's surgery to replace the lost hair (with hair moved from somewhere else, granted). It's certainly much more expensive than catching it early and treating it with minox or whatever, but it's within the reach of many people (<$10k).
So you need endless treatments, or else take testosterone blockers.
It's a meme at this point, but for most people shaving their head is the right option.
1. even back of head hair thins eventually in balding people, but generally many decades later than the front or crown. By the time you're losing that hair, you're probably a lot older and care much less
2. taking finasteride indefinitely is supposed to drastically slow or stop further thinning or loss. Of course as in point 1, you're probably going to lose that battle eventually, but again you'll be much much older when the damage gets serious than you would have been otherwise