Man, I felt this stuff a lot when I was in college. Coming from a lower middle class family in a poor state to a private school in California, there were so many little things to make me feel like an outsider. The part about hobbies was the most memorable because it made my social anxiety worse early on. I always struggled to think of something more interesting than "video games" or "reading". And, of course, the food stuff. Took me years to get into the habit of ordering a salad when out for lunch like a civilized human. But unlike the author's experience I was so much better off than many Americans with backgrounds like mine because I went to a private university that provides enough financial aid to students who need it. So for the most part, I was already better off in college than I was growing up, and I graduated with a manageable amount of debt. But there were times when my family needed a little help and I was scrambling to find some free food to get through to the next paycheck or wondering if Mom would pay me back in time to make the phone bill. I also wasn't the "only poor person" around, and I found others like me which really helped.
I think all the useful political points have been made by others but I think it's also worth saying whatever happens with society overall it can get better for you personally. I hope others who relate to the post find a job that values them enough to start chipping away at the accumulated disadvantage. Once the major financial stress is removed, you can and will acculturate, start worrying less about these little things, and even become more like your peers, and I think it's ultimately a positive thing. These cultural markers are, in part, adaptations to the situations we're in, and if you're working in tech it makes sense that you will find things that newly resonate with you and shed some of the things inherited from parents whose work society decided to value less.
Of course there is at least one serious obstacle to this, which the author astutely points out and which I don't have any good advice on because I still struggle with it:
>I knew I was the only poor person at my tech startup because I was afraid to seek mentorship from anyone above me, convinced that even asking would seem like bothersome begging. I watched the people around me network effortlessly, assured of favors and good words put in. I could only think in terms of what I could offer and how I could survive; they were thinking on the next level where they never had to wonder if they were good enough.