4) IT (all areas) has been commoditised.
IT is no longer seen as valuable. A few decades ago it gave a company a competitive advantage. Nowadays it's seen as an undesirable cost (which then leads to point 3).
That just isn't true, look at any richest people in the world list right now, look at who the top people are - IT nerds!
Look at where Prince Harry just got a job, a decade or two ago a prestigious job might have been at some big bank or consultancy, these days a C level role in a tech firm is fit for a Prince.
There are plenty of tech-related roles in very high demand right now from security professionals to data science... there is always demand for
good developers - a
good developer has a heck of a lot of freedom, generally a fat salary or daily rate and can change employers very easily.
Even mediocre devs and BAs in London can opt to go contracting and get the standard-ish £500 a day + or - £100.
Good developers (or BAs) with in-demand skills can get substantially more in the contractor market.
As for start-up employees or indeed salaried professionals at private companies that later go public they can end up with some serious wealth if it goes wrong... I know of someone who spent circa a decade in the same company as it grew (not a high growth start-up or anything, just a regular, profitable, private IT company) - he had stock options and made use of them over that decade... the company then went public, he's a multimillionaire now and never needs to work again. He wasn't a founder, he didn't join some high risk, high growth firm... he was a regular joe starting in some grad role at like 30k a year and then over the years working his way to a middle/junior management position with responsibility for a small team.
I think the problem is people think of "IT" as - people who fix the printer etc.. and there are career paths within the broad umbrella of "IT" that involve working on a help desk or doing mundane jobs + collecting vendor certificates in order to do more mundane jobs... then eventually working your way up to a position where you're an expert in fixing mundane stuff and you're only called to fix the particularly tricky things that the layer or two of minions below you can't fix.