It doesn't have questionable rates of success. Check out studies/researches, anecdotes on reddit.
Whether it is a life sentence or not is debatable. People growing beard with minoxidil retain their hair after they drop minoxidil given their hair are terminal not vellus.
Morever, I've seen people retain hair after stopping minoxidil., but they consciously or unconsciously do sth for fibrosis and calcification (like massaging or derma rolling etc) or they take Finasteride.
In India it cost me roughly 600rs or 8.5$ for a monthly(?) supply of MorrF which has minoxidil 5% and fina .1% as its ingredients, and it certain is not costly. However, for most Indians, it may be mildly costly, since we're not a very developed country yet.
Its rate of success is based on studies. When used on its own, the effectiveness is insignificant; in my opinion, medications which can't be used on their own shouldn't be classed as a viable option.
It is a life sentence, since there is a difference between beard hair and scalp hair. One of them is being attacked by androgens till the point of miniaturisation, and one isn't. It's similar to topical minoxidil being used to treat telogen effluvium in female patients, and then having the ability to drop it since miniaturisation wouldn't occur. That situation would not be applicable to someone suffering with androgenic alopecia. Realistically, it's finasteride/dutasteride which provide sufficient results.
In the country I live in, topical minoxidil is costly. And it's costly because it's not worth the money, especially since finasteride is cheaper and dutasteride is slightly more expensive. But, they both provide significantly better results.