Incels were less common because the hypergamy was limited due to the fact that foids only could choose from their social circles or from their going out moments (no tinder back then, impossible to have a thousand-men variety of men to choose from that you could fuck the same day). Since they were in social circles it was extremely hard for them not to have their friends know who fucked them and when, while today a foid can say she's a virgin and people will believe them while their bodycount is over 9000.
Another important point is that the global population amongst men was reduced due to the WW2, resulting in less 30-40 years old chads. You may not know it, but since the beginning of times a lot of toilets from age 20-30 have had at least one relationship with someone who's way older than them. This is still true today, foids tend to prefer men who are older than them, and the threshold can reach 40 years old for 20 years old foids. These older men "steal" toilets from people their age, hence the extremely high amount of virgin men at the ages 16-23 these days.
The male-female ratio was unbalanced by the war, with many more toilets than men compared to today.
Boomers have had it all: Full employment, wealthiness, no woke/feminism, accessible toilets even if men were ugly; the invisible line separating a man from an incel was extremely lower than today, and to be an incel in those days, you really had to be physically deformed, suffering from physical abnormalities.
Moreover, toilets were still wrapped up in the notion of the traditional family circle (and the boomers worked their ass to destroy it, because toilets wanted to fuck chads and delusional normies thought they would experience what chads were experiencing back then already), and were much more monogamous than today.
We pay in every way (not only incel ways) the delusions of normie men back then who allowed women to dictate their wants and needs. 80% of our society's problems are the result of boomer scum born between 1945 and 1960 who lived in the kingdom of Babylon believing that it would stay that way for eternity. And saying that they believed in that is really a nice way to put it, imo some knew, maybe all knew it wasn't going to last forever, but they were just extremely egoistical.
In concrete terms, this is why the emergence of incels dates back to the 1980s and the end of the wars that claimed hundreds of thousands of male victims.
On the other hand, the number of incels in Russia and Ukraine is likely to fall drastically, and this war is "good news", since fewer men in Europe means more toilets to share. The war in Ukraine will have a positive impact on the whole of Europe, unfortunately not enough to solve the phenomenon, but over the next ten years, this war could very marginally an temporary reduce the number of incels.