This is fair. My "lab" domains get almost no traffic. If someone wanted to knock them offline they could and Hetzner would null me. Not a secret, part of the "don't do this" framing.
Mini-guide: $15/year box as primary nameserver—don't, but here's how
In Turkey Hetzner billing is awkward. No TRY, card gets hit with conversion both ways. I use Contabo for cheap boxes instead, 3.99 EUR plan. NSD same config.
Contabo is cheap because they oversubscribe. You are on a bus with fifty other people calling it a limousine. Fine for DNS maybe, but know what you are buying.
I know. I said I use them, not that I love them. For my backup NS it is acceptable. Primary is elsewhere.
I learning with BIND first. It is very fat yes. 400MB just to start. Now I try NSD on 256MB VPS from local provider in Da Nang. Works good. Thank you for config example.
In Poland we have Domena.pl and AZ.pl that do secondary DNS for free if you register with them. No need for second VPS. I never understood why people make it complicated.
In Hong Kong most use Alibaba Cloud DNS or Tencent Cloud DNS. Free tier, anycast, five POPs in mainland plus Hong Kong. Why run your own at all for a small site?
So I should just use my registrar? I thought running my own was better
It is not better. It is a hobby. For a bakery, use Cloudflare or your registrar or whatever jasonjab said. The end.
Following.