I don't know how to not care. I've been writing software since I was a teenager and it's always been a central part of my life. I've always cared and that care is partly what made me successful (or so I believe). But it definitely is also what's stressing me out... I've always seen work as basically being able to be paid to practice my hobby though as well all know(?) your fun hobby becomes less fun when it's work.
I remember having lunch with a co-worker who was saying something along the lines that he's never really wanted to code and the only reason he's doing it (got a degree and a career) is for the money and I didn't understand how that was even possible ;)
I mean, there have been times / places in history where you work so that you have enough money to not die; and you enjoy your life with whatever pittance is left afterward.
I doubt anyone reading this website is in such a time or place.
As such, I have trouble seeing why you'd think any work you do means anything. Most likely it doesn't and that's okay. It is not within your control to have meaningful work available. It is within your control to have a healthier attitude towards your workplace and your work.
If I can earn more on some side work or investment and those earnings are stable enough, then I too will not care about work.
There are so many ways to find a real meaning.
Be a great person, help others, read a book, do yoga, help kids with homework, plant a tree, build something with own hands, grow food, clean-up trash.
So many things to keep you busy. Work is just a necessity to do something that actually matters in the longer run (for majority at least).
Ppl that deeply care about the company and product are such a tiny minority.