The 1st job.
The first time you feel the benefit of earning. Where, unlike good behaviour and household chores earn pocket money at the end of the week, this step up is an individuals first foray into the real world and reinforces the importance of delayed gratification and realisation of accepting this principle if any success is to be acheived in the real world.
In a far left utopia, the question won't be when your son/daughter finds their first job. It will rather be cart before horse like, when their dream job or "calling" will find them. Which, given they won't take that much more progressive (better believe ironic pun intended) move towards working life it has consequences. You never miss what you never had, but they will never have; that useful comparison that helps them in future when in a "good" job they have a bad period, to help them think "yeah it's pretty rough at the moment, but still heaven compared to a good day at that first job." Resilience.
They will never have that "wow, I've really come a long way" where we learn to measure against ourselves and our journey. Be that further up the ladder, or to a job that more soundly fits our lifestyles. Mistakes likely made along the way, but getting to this point can be spine tingling in affirming the progress made. Determination.
Never will they come across the plethora of people from different backgrounds that can make life long friends. Appreciating, at a minimum, a good worker. Even if they don't necessarily get on in any other ways. Open mindedness.
In the liberal unfolding of such an important milestone, not only may it never even occur (there's 7 billion plus people in the world, it's a long shot we'll all find our exact calling...even longer that calling will be fulfilled in the first attempt). But if it does, then how many lawsuits will be filled under; offense taking, gender "misrepresentations", restricting of the need (nay, rights!) Of people to express themselves. All the above is far left dystopian future speak for "I'm struggling, I've never done this before...but I don't need to improve, you need to change your business." The lack in humility aside, there are so many traits that will...ready?...progress the person.
I guess if this future were to unfold, lawyers may well benefit. If, of course, they can ensure the effort required to get to that level.
The first kiss. Usually looked back on fondly, if accompanied by a slight cringe. It's the chance to say in later life "oh God, I found them attractive?!" Or "he/she might be the hot thing now, but they smooched me back in the day!"
It's different for everyone, but it ultimately brings the genders together when you recognise the mutual nervousness those you've found so different for so long early on in life. Bridging gaps.
Let's look at the far left sway on this milestone. First off parents would likely warn their girls of the danger of boys and everything inherently wrong with us males. Which, for a lot of girls, will inadvertently push them towards getting a boyfriend. But when said boyfriend comes across as apprehension due to the things he can't do or even say without explicit permission and the minefield this looks like to a young boy will look very bleak at least. At worst divisive beyond recognition for us by the time we have grandkids.
There are many more milestones, losing virginity, marriage, first "career."
Missing out on true progress (by the current definition).
The only benefactors I can forsee would be lawyers who have, along with the law itself, been indoctrinated with political correctness from a young age. As a side effect, will also live a life of watching their back. The other potential benefactors, rather than being afflicted by a lifetime of being pensive and cowtowing to the fashionable group of the day, will have to accept or short term future. Which, frankly doesnt sound too unappealing if the far left do get their way.
The MGTOW members who will either have to die out or have children via laboratories which they were able to fund via their law careers that they detached (without being "offensive" ...ever) themselves from.
As much as I see the motivation behind men checking out in a world pitted against them, there isn't a long future in it. And lawyers need common sense and honesty injected into their practice not all out avoidance of it. See judge Reed O'Connor, judge Jeanine Pirro, justice Scalia. Hell, even judge Judy! Stellar examples in the west to help us avoid this, weak charactered, sheltered life, very very viable to be taken over by hostiles, future.
I hope my far left ominous prediction is never fulfilled but just in case, I'd suggest everyone equip themselves with the lessons taught by the above people. And in additio to them, the lessons of those a lot less fortunate already living in far left utopian communist countries and how those very few (somehow) managed to escape. With life long scars no less.