Low T for most men is a symptom of dysfunction, that's being presented as low T, i.e. it's usually being caused by something else. Typically men will treat their low T without finding the root cause and will not address the main problem. They'll then feel better for a couple of weeks and may still not feel good, even after getting dialed in.
Many guys never even get dialed in because of inexperienced doctors and the need to self educate and run your own independent blood tests. Many struggle the most with controlling their e2 because without patience and diligent dosing and follow up testing, many symptoms of low e and high e are similar while you're experiencing them, making it very hard to differentiate.
A lot of guys likely have thyroid, adrenal, gut, chronic inflammation issues that result in low T.