You could do those jobs practically anywhere, but fast-growing tech startups tend to pay relatively well (at least as well as established players) and throw in a lottery ticket.
If you enjoy wearing a variety of hats, like you'll need to in a smaller company, you might as well do a couple years each at a bunch of different startups and collect lottery tickets along the way.
People don't tend to get rich in support jobs, but a bonus of even a few tens of thousands of dollars can be a game-changer, and on the off chance you catch a ticket that ends up being worth a couple hundred grand (what happened to me that made me start recommending this!), it'll change your life!
Rarely will a customer support role be offered shares that are worth more than a couple grand at the time of grant, and it's not always worth sticking around the whole vesting period, but if you get in late enough that the company has proven product/market fit (Series A and following, at least a few dozen employees, 3+ years), it probably won't go all the way to zero.
You don't get to just collect multiple lottery tickets without either going out of pocket or watering down your share significantly.
Both of the last two companies I worked for, it cost me about $1,500 to exercise the shares I'd vested after about 2 years, and their 409a FMV was about $26k at the time I exercised them.
One of those companies has since gone public and my piddly little $1,500 became worth over half a million dollars.
It's absolutely a lottery, but if you get in places at the right times, I think it's worth collecting tickets rather than doing the same work for similar pay where you don't get tickets.
% needs context of how many other employees there are and what the valuation is a grant time.
The signal is about the founders themselves, which is an important consideration when joining a startup.
Number of shares and current strike price + latest valuation, along with any practices for minimising tax burden, are still hugely important pieces of information. My point was simply that even just the percentage tells you something about whether it's a good company to join.
Typically the company tries to keep the strike price of common options as low as possible, to the degree the 409a consultant will let them.