I definitely needed financial support from my parents during internship. I was at a low paying private practice program in a state with a high cost of living (which I’m sure is only worse now, since I was an intern eight years ago). My rent was $1200 and my monthly take home pay was barely over $1600. My parents paid for my gas, car insurance, phone, health insurance (because I wasn’t 26 yet) and more than one grocery trip. Most months I could scrape by, and honestly as an intern I was too busy to do much more than work and recover+grocery shop on my days off.
As a resident in academia, I was in a lower cost of living area and the salary was like 8-10k higher. My parents did still pay for my phone and gas and flights home for the rare visits, but it wasn’t as difficult to afford to live. There wasn’t a lot left over month to month, but I could afford my bills. I managed to pay slightly more than my income based minimum on my student loans during residency. I didn’t have any major pet health crises but my program gave good discounts and had pet insurance. Again, there’s so much for a resident to do that I didn’t do a lot outside of work, reading and studying at home, and resting. No expensive hobbies, no fancy trips, or anything like that but it wasn’t awful. I went home once or twice a year but didn’t take other trips. I ate out some but not a lot.
As a single person, I will say that it seemed to me (obviously outside looking in which has its limitations) that those residents who had a significant other had an easier time of it, purely because they have someone to split rent and share bills with. If your SO is in school they can get student loans or if they’re not they can work which could help immensely. But it seemed like my friends in relationships had nicer housing and more discretionary income for sure.