So I'm 20 and I've started looking at the salaries of jobs/careers, and this is the impression I've gotten. Like that you could spend years cramming a ton of knowledge about a very niche field, and still only get 2-3x what a run-of-the-mill job makes. Is this true? If yes then I guess this route to wealth would only make sense (due to the diminishing returns) if the topic truly spoke to you, right? Are there alternative career paths to good pay than being really good at something really specific?
It's hard to overstate how much money "2-3x what a run of the mill job makes" is over the course of a lifetime. I guess to you right now it doesn't seem like much, but someone who makes three times more money than someone else is significantly more well off. There aren't any wage jobs that are going to net you exponential salary growth. Your only hope there is to strike gold and found PayPal or Microsoft or something.
To build on your comment: cost of living has a surprisingly fixed price. Different qualities of living don’t cost massively different. If the average person has to spend their whole earnings on living an “average life”, if you make 2x and want to live twice as nice of a life, it likely only cost 1.5x the “average life”. Earning 2-3x opens up a lot of luxury even though it may not seem like it.
This is very true
Some people fall into the lifestyle creep trap and get accustomed to spending what they make. If you make 2x average and live relatively normally you’ll find your savings grow quick.
Even if you do make good money, it’s best not to let that go to your head.