As a middle-aged (late 40s) only child with aging parents--both of whom have serious medical issues as well as early-stage dementia--I can tell you that what you might find find suitable for a minimum bare-bones existence in your 20s will change dramatically as you age. I make a pretty decent living for the hours I put in. I enjoy my job a great deal, and I am terrified of growing old and running out of money in old age. In addition to pension (a rarity these days), my wife and I are also piling money into our retirement accounts at a rapid pace. There is an old saying--something to the effect that being young and poor is quite a different scenario than being old and poor.
In addition to that, circumstances change, life sucks sometimes, and you need a substantial cushion of cash to avoid going into debt (slavery) or worse. Budget for the worst-case scenario, not the best! Just look at what's happening now with COVID, people and businesses going bankrupt, disappearing, etc.
You should also consider that in your early years of your career, you are paying your dues to a large extent, and what you find meaningless now may turn into something you enjoy and make much more money doing as you gain experience/seniority/connections. etc. I got a Ph.D. because I love science and I spent many years paying dues in grad school, postdocs (which were also awesome in some respects), etc. I was not too enamoured with my current job as university faulty at first, but with increasing pay, job security, a nice office, seniority, etc., I feel a lot better about rewards matching effort. I also greatly enjoy relating to students, something I had problems with at first--As a result I am much better at my job, and my efforts are a lot more rewarding.
I too talk about early retirement, but I have likely at least another decade to go, but I can be happy in a job I enjoy with lots of free time and autonomy (I realize this is a bit of a rarity!). My main reason for wanting to retire early is that I want to get the hell out of SoCal, which I hate and detest with a passion. If classes remain online for me, we could move to Ireland (I am a citizen) or NorCal. Hopefully that will be sooner rather than later!