Testosterone is very easily manifactured hormone (luckily), quite a simple mollecular structure.
And speaking of brain not producing, well it does happen for most males over 40.
As for african males, there is a very extensive (not making up, could find if you are interested) big study who completely ruled out testosterone as a possible cause fo canre. Actually vice versa - it may be a lack of it (and higher estrogen) which is exactly what happens with age.
It's really far from obsolete negative, that is for sure. Used with a proper provision and regular check ups it may be one of the best things to do for staying healthier/younger for longer.
I agree with your points that there is plenty of studies that also show postive benefits to testosterone supplementation. No need to post up the studies I have seen some of them, I dont want to get into a pissing match

After all this is getbig and not a serious bodybuilding forum

I've had a few too many of these conversations before posting studies back and forth on proper bodybuilding forums.
I realise that for every study I post you can post one that suggests to the contrary, thats pretty much nature of research with everything, conflicting evidence and restults. There is a differing of opinion, in the US, the concept of TRT for men is accepted far more so more than in the UK and Europe in general. One thing I would say is that some of the studies on men that have shown positive benefits have been on men who have made no other lifestyle changes other than take TRT.
The question is what improvements would they have made in their general metabolic parameters if they had made other lifestyle changes, ie weight loss, exercise, diet, cut back on alcohol etc. That is really my point. I think that for many people with low test, they should make other changes first to optimise their health, dietary, exercise and otherwise. If after all that and they still have problems, then TRT could be a possible avenue of treatment.
Assuming that a person after making all these changes still had low test what do you consider to be a reasonable "dosage" would you consider a testosterone patch to be sufficient, or more. From what I have seen, a lot of men are not using TRT to "normalise" their levels but go beyond to a point they are gaining more muscle than they had before which would suggest they are moving into the realms of dosage found with recreational bodybuilders. I havnt seen any studies which have compared the effects of TRT dosages used to normalise test levels, vs higher TRT dosages which put people into anabolic state. Perhaps there are some out there, I dont know what the results are, but perhaps there is probably a threshold whereby the therapeutic benefit drops away and sides start to take place.
Anyway I said I wasnt going to get into a pissing match and I have just started going on again, I will shut up now