It took about one year to find efficient ways to treat COVID-19.

So, if you have a condition with a few years of life expectancy remaining, maybe it's worth it to wait for some promising scientific results to turn into an approved medicine that will cure you. If you have a few decades (e.g. the normal life expectancy), even more so. If you doctors give you a few months though, maybe the "try anything" approach is a better gamble.