It's also wonderful for less serious works, like history of some video games, where the original sources may not even exist anymore besides the latest snapshot of the Web Archive and their only use is on Wikipedia. There's a probable 0% chance that you would find an equivalent with a regular web search.

Source : I'm the guy who wasted 3h of their life trying to find a non-primary source about Hypixel's four Guinness Records to know what granted them the "most games on a Minecraft server" record. Ended making an account on the Guinness to access their free search engine and it turned out the authoritary source is incomplete from the start. I assumed somebody better would find a good alternative, but the "free registration required" link and the technically unsourced warning about the missing info still stands there years later.

It's crazy how hard it is to comply with *usually* sensible Wikipedia rules when there's no third-party media coverage of a fact. ^(If you want to help with wikipedia, don't fear asking in the talk page! It's there for a reason!)