Not everyone is wired that way. Personally, I have taken apart and reassembled most of the tech stuff I have at home simply because it interests me how things work (and broke and repaired a non-negligible amount of them in the process, to add), I've dabbled in repairing cars, gas boilers, do my own electricity work... but in my social circle, I'm pretty much the only one. And as I grew older, managed to land myself an s/o, I kind of get
why - two other parts come into play:
The first issue is a lot of acquiring broad-spectrum knowledge involves risking quite an amount of money. A good DSLR cam can easily rack up a few thousand euros, a fully spec'd Mac Pro or larger drones cross the five digits without blinking. Messing around with gas and electricity can kill you, messing with water pipes can cause immense water damage. It takes a lot of ... let's say recklessness to even think about dealing with this if you're not a professional, and you have to have the resources in the first place.
But the real issue is time. Students, at least here in Europe, don't have the luxury of taking six or seven years for their basic diploma - "thanks" to the Bologna reforms, you're fucked if you can't make it in the designed timeframe as you won't be eligible for most kinds of financial aid. That means you simply cannot afford "wasting" a week to get that deep level of knowledge, you simply are happy enough if it runs well enough to get a passing grade. And once you've entered the workforce, it becomes even harder to have actual hobbies. It's one thing if you live alone, no one will bat an eye if you pull in an all-nighter on a weekend with just yourself, a crate of beer and a laptop and that's assuming you're not completely drained from your average 40 hours work week, 10 hours of getting to the workplace, and another 10 hours on domestic chores. When you live together with another person, the game completely changes: they also want time and attention from you - bonus points if your s/o has roughly the same interests that you have (which is why I suspect so many people meet their s/o at work). And with children... forget about hobbies of any kind if you don't have enough resources for either yourself or your s/o to be a stay-at-home parent.
This is why I so strongly advocate for a four-day and six-hour work week, a proper minimum wage and government-subsidized affordable housing for everyone. Just imagine what useful things people could run as side projects if they actually had the time to pull them off, not to mention the obvious physical and mental health benefits of not having to struggle with survival every single day. Add to that the elimination of "bullshit jobs" and an end of wasting the best minds of the world on financial bullshit (i.e. HFT, "quant investment funds") or advertising... or getting rid of racism and other discrimination. We as humanity could make so much more progress if we were not so hell-bent on exploiting each other.