Wilhelm Reich's sexual revolution became a reality in the 60s, but sex isn't magical orgone fairy dust, but a biological function like any other. Hunger, thirst and sleepiness are not by themselves revolutionary. capitalism can exploit them and twist them for its own ends, just like it does with sex.Turns out the ' the unleashing of desire' doesn't necessarily lead to people having more sex.
Engels was inspired by the theories of Johann Jakob Bachofen, a 19th century swiss anthropologist, with a romantic, highly eccentric approach quite distant from modern science, think Robert Graves' theories about 'primitive matriarchy'. depending on who you ask, he's either a proto-feminist or a reactionary woman hater.
Much of leftist social criticism is directed towards a vanished bourgeois social order that has been for the most part replaced by the cybernetic society. There is no clear break, but the failure of 60s radicalism and the neoliberal counterrevolution in the 80s might be useful guideposts. Reagan's debt to the Hippies is often underplayed.
The modern 'destruction of the family unit' has been less a product liberation and more a result of the general disintegration of social bonds. you've perhaps read this meme article:
it's impossible to know how post capitalist social organisation is going to look like. attempts at top down social engineering are just likely to provoke a backlash among people who've had enough of market driven social engineering already. capitalism has a practically unlimited ability for the recuperation of all sorts of lifestyles, regardless of how 'subversive' they might seem. Besides, being 'subversive' is not a burden that should be placed on trans/gay people. Much of popular 'leftist' and 'feminist' thought of the last half century has focused on telling individuals about the proper way to be free and liberated, which also means placing restrictions on what they should and shouldn't do. Women are in some ways, better adapted to the current form of post industrial society than men.
the 'pop feminism' found in mainstream liberal publications more often than not amounts to a never ending paean to narrow market freedom and a corporate fascist ideal of leadership out of reach for most women. Note the Hillary campaign's use of the imagery of 'poptimism', the courting of popstars, slogans like YAS QUEEN! apparently it wasn't very effective outside of elite costal liberal circles: most white women (at whom the campaign was targeted) went for Trump.