The pursuit of happiness won't make you happy, but the pursuit of *improvement* will. Improvement in skills, in relationships, in general health, in anything. Getting a tiny bit better at something you were worse at yesterday is scientifically proven to make you happier.
Yes, I wake up every morning grateful that I don't currently have to worry about paying the bills, always have enough to eat, and live at a standard kings of yore could only dream of.
I also know that when "just be grateful for what you have and want nothing more" is preached, people live their entire lives in boredom and poverty. I've dug my way out of that hole. I want more.
Yes, you're entirely right that the minute you hit average wage, your life changes. The minute you can meet your immediate needs without fear is the minute you start to think, "What else do I want to be doing?" and that's where you move from surviving to thriving. You don't *need* a quarter of a million - nobody really does - but "very slightly above average" is bloody convenient, especially in a pandemic when you get hit with unexpected bills.
Much has been made of how smart people are often unhappy. I have a hypothesis: memory and emotions are strongly interlinked (as explained in Inside Out). People with heightened emotions are more likely to have better memories, hence appearing smarter. I know plenty of very happy, exceptionally clever people who have accomplished great things - but they don't try to be "the best", only their own best. My role model says "what interests me enough that I want to do it next?" rather than "How do I compare to others?"
There's high-paying jobs and high-paying jobs, and a reason why the rest of us say, "Jeez, if a paycheque was all I cared about I'd work in a bank!" Several friends are in senior management at a top video game company. They're the happiest people I know.
One thing I have found valuable, by taking that what-interests-me path is that it largely makes me redundancy-proof. I don't fit in the set mould, but because I dabble in most things, I can do almost anything. That grants me a freedom from fear that most people around me don't have.
And, ultimately, happiness is a combination of "flow" (improvement) and freedom from fear. So, throw yourself into those hobbies - you never know when they might come in useful.
