Theres restraint and then there's also suppression. You can find encouragements to restrain oneselves going back to proverbs in the bible or the ideals in Roman society.

Although controlling yourself was seen as advantageous in general, men were not expected to supress their emotions, quite the opposite. It was fine to be angry or vengeful or lustful or in love etc just as long as it was directed at someone lower in the social hierarchy.

Christianity probably had a hand in supressing those outlets, though looking at history is doubtful that the majority of the population were 'pious' like that.

Where it seems to have taken a notable turn is during the Victorian era. The social expectations of 'proper' behaviour started to constrain the outlets men were 'allowed' to have. Not just on the battlefield, where controlled marching into musket fire was more important than ever, being stoic in everyday life was becoming an ideal to restrain vice. Prostitution was becoming more taboo, as was gambling, and violence in general.. at least in "civilised" society. Which in turn was possibly driven by the industrial revolution moving everyone to cities where living close together made these "sin"s more visibly awful.

Warfare had always been awful, but there was honour in man to man struggle. What got far worse from the 1700s on was needing an army to not crumble in the face of impersonal volleys of musket fire and canister shot from batteries of canon half a mile away. The era of feats of strength was over. Now you could get horribly mangled at random for standing in the wrong place. This was the origin of the British "stiff upper lip", the ability to meet misfortune with indifference. The beginning of widespread supression of emotions.

From the Victoria era, add in half a century of industrialised warfare, the grimness of which had never been seen before. And by the 50s/60s society was dealing with very broken men who had been traumatised and given no better advice than "be a man and suck it up". Which has disastrous consequences, not just for men but also domestic violence and abuse or neglect where things tipped over.

The hippie movement rediscovered men's 'softness' but wasn't practical. The eighties was practical - created an outlet in the deregulated business world of working ruthlessly and making personal riches - but it lacked "wellbeing".

It's really only in the millennial and gen z generations that this historical trauma is distant enough and society's ideals have changed enough that we can even begin to have public conversations about men going to therapy or crying on a friend. This would have been sappy even in the 90s.