Ah, ok, well, can't wait for that to happen to me :D

So it seems that Researchgate gets a bit spammy for senior scientists, but my naive perspective (as someone with an empty postbox on Researchgate) would be that these are maybe people asking for copies of paywalled articles?

Hard to say because, as you say, it's hard to disentangle rising expectations and response quality. Further, as prompting improves, bad responses become less frequent and are quite a "shock" when happening.
That being said, yesterday I also had a frustrating experience, it just rambled on nonsense.