Sure, but that's time consuming and often too specific: Kagi lets me push sites I trust results from higher without limiting the search to a specific single site. It also explicitly looks to rank blogs by individuals higher than corporate websites, so it's more likely to surface that niche how-to by someone else who has been there.

Takes me less than a second or two to type site:<whatever> in ddg, I'll survive. It has been sufficient for me.

Sure, but what's more helpful than that is being able to blacklist sites from the results and being able to say that certain sites should be given greater weight, which Kagi allows.