In principle, you don't even need a "server", ie purpose-built hardware like what he's showing. An old laptop will be fine for many projects, although I'd be interested if someone can help put a perspective on how to decide whether your specific project/load will be too much for your specific hardware. My bigger concern with 'true' self-hosting would be how to get a good/reliable enough internet connection.

Our infra runs on 2 12-Year old shitbox Poweredges. so yeah most is just overkill.