A very relatable and great youtuber is chicprofessor. She buys almost exclusively preloved and not like the brand new preloved kind either; she buys bags that have wear and sometime are missing straps, and likely a lot more reasonably priced for being "imperfect" for the average person, and she's honest about her interest in sustainability and affordability. Her collection is also well-curated to her lifestyle and has a broad range of brands. I really like her.
I agree with some previous posters that when I see a VERY young youtuber who talks about affording a birkin on a part time job while in college (and they live in a huge, well-furnished apartment while still in college), i see red flags everywhere, and I really don't believe they can pay for it all without familial help. And here's the thing; there's nothing wrong with having that trust fund money! If you're lucky enough to have it, good for you, buy the bags and show us (because that's what we're there for at least in part), but don't fake humility and pretend that you don't have money to rely on. Just my two cents.