It is important to note that all of these men, save for Nate Diaz, are using some sort of steroid. Good genes and years of training can result in a physique similar to Belforts, but his traps and shoulders are still indicative of steroid use.

On a similar note, I wonder about the morality of modern man using testosterone replacement therapy. Testosterone levels have plummeted in the last hundred years (microplastics? sugar? something in the water?), which may be why you see so many pudgy men with breasts who hold fat in all the wrong places. It seems to me that using TRT would simply be getting your testosterone levels back to where they rightfully belong

I was thinking of someone with "normal" T levels, by modern standards, using it for muscle gain. If that would be considered vain or not

Like so many things, "it depends."

Baseline free testosterone at onset? Total testosterone levels are worthless because most of the total is bound to SBG sex-binding globulins; it is the free component that is physiologically effective. goal level  at steady-state treatment? If low initially and goal is normalization, few problems. If normal initially and goal is supra-maximal levels, more problems.

Diversion of testosterone into the female hormone pathways?  Some use anastrazole, an aromatase inhibitor, to block diversion of test to 5HT (baldness) and female hormones (boobs). Anastrazole is far more danger to the heart than testosterone itself. Testosterone used to be a standard treatment for cardiac ischemia.

Manner of test delivery?  repository oil injections? = oil microembolism problems and markedly fluctuating levels.  pellets? even more wildly fluctuating levels with supra-max levels with initial pellet placement (trochar injections anyone???) topicals? = spousal exposure (sleep in the same bed, linens, body-to-body contact) = double-edged sword = increase wife's libido v. virilize wife  application site? wives report that taste is an issue for a particular standard application site  which topical? alcohol-based vehicle? ("burns" so limits available application sites) compounded cream? (oooey-gooey but doesn't burn, vehicle not as well absorbed)

testicle shrinkage (think "raisins")

There are so many serious considerations that a doctor's visit (with a knowledgeable doc) makes a lot more sense than generic online or gym rat lore (and illicit sources).

P.S. As for protein powder, rarely justified. I hoard some as a hedge for the family against kwashiorkor in the times of hunger ahead. If someone can afford protein powder in the USA, they can afford a balanced diet and have no need for protein powder.