nprofile1qy2hwumn8ghj7un9d3shjtnddaehgu3wwp6kyqpqch8hfpny6tp95jqut4smklg3nx2h93dvvw6x4jsaqzwj8u6az9lq40qmju (nprofile…qmju) I agree that, for math related questions, this isn't probably as big as an issue as in the general case. For the reasons you mentioned (even if not all math can be formally verified [yet?] AFAIK) and because the users asking for a specific technical question usually have the technical ability required to check the validity or make clarifying questions. But even in this technical contexts, if we for example look at programming tools where responses are automatically tested by compilers and static analysers, researchers have still measured a reduction in quality when using them (with a small productivity boost).
Yes, the quality problem with online (or even printed) resources always existed (Wikipedia used to be considered unreliable when I was younger for example), but generating content was more expensive and it was easier to estimate how reliable were a particular source.