Search functions vary widely in utility. Companies have built their almost-world dominance on them. Well OK only one really, but others have done so regionally (Yandex, for example in Russia).
Plenty of search systems are trash. Wikipedia’s used to be terrible and has moderately improved since then. Tumblr’s is (evidently?) so bad that some themes even satirize it.
Sometimes, like this one below, the problem isn’t the search function, but an overzealous application of it:
When you only have two possible options, a search isn’t really required, IMO.