Different industries have different customers with different needs and funnels.

None of my businesses use a "sign in with..." option and I highly doubt it would increase conversions, however the article and many commenters here are adament (based on their experience) that it is integral.

I'm not sure it's day trading per se, I think it's just a lot more relevant to some industries/products than others.

OP is talking about apps distributed through App/Play Store though. After a certain size in B2B services, sure, you can do Google Ads. But even for B2B it makes no sense to start out with it unless you're a hot startup raising big rounds. The RoI isn't there in 2026, the juice has been squeezed.