FIRE isn't about job market, you can't control that. Though in tech most people are still making quite large incomes which does help.
Rather it is about controlling expenses. The thing you can actually control. My sister's family of 5 lives on less than 50k CAD / year, because they simply must (low income) so if one is making a 100k white collar salary (for example) one can live a lifestyle higher than hers while still banking 50k/an. Etc.
FIRE is definitely about income just as much as it is about being frugal and saving. Having a high income is what enables the RE part.
There is a base level beyond which you can't save much, so first order of business is maximizing your income (e.g. better job/raise/promotion) without going bananas and sacrificing your health for it.