Employees that are seen as important get equity all time at the most successful companies. The founder keeps majority ownership but it is normal for equity is normally shared to keep people loyal and motivated. Random tesla employees have gotten rich and i know private companies that split profits according to equity.
you're making it sound like equity is easily attainable. true equity (not some shares that get thrown around) is not easily attained at all.
like you said, it's reserved for employees who are deemed important. that is not a large group of people. and then the biggest/best equity packages are normally reserved for the most important employees. so even within that already small group, there's a huge difference between employees who get handed 10,000 stock options, and the most essential employees who get 60-75,000 restricted stock units that vest on a faster timeline.
and even those units pale in comparison to what the CEO receives.
then, when equity IS more attainable, it's usually awarded to compensate for the company paying at a lower scale than industry standard. so you're trading money upfront for (potentially) more money in the long-term. but you have to stay with that company 2-4 years to collect. and even THEN, if you leave you have to buy that stock from the company in order to keep it. they don't just give it to you.
equity is not thrown around. like everything else in corporate it is a negotiating point, and you get what you negotiate for yourself.