Where I come from (and in other countries in Latin America) you can buy bitcoin directly by joining a Telegram / Whatsapp channel of people who are looking to either sell or buy.

That's what I do. You bring cash, they send you bitcoin, done deal. This is the only way I have ever purchased bitcoin.

Or, take for example, my friend, who was going on a sort of expensive trip and needed to sell some bitcoin that he was holding because he ran out of cash. I happily bought it from him.

I used that bitcoin to purchase web-hosting related services and a few physical goods in shops that I saw accepted bitcoin. Again, to my surprise many services accept bitcoin, not just shady ones but reputable ones like ProtonMail / ProtonVPN.

Now, I'm not saying this model works for everyone and I know we're nowhere close to mass adoption if it were ever to happen. Bank statements are very important for certain things (applying for loans, visas and residences to different countries) but I for one keep less and less money in the banks. I talk around locally to people and see who is interested in bitcoin, surprisingly more people than I thought know about it, but of course, still not enough.