Bouncy bumble bee, your list made me smile because it contained my grammatical pet hate - the confusion of less/fewer!
‘Fewer’ pertains to plural, hence ‘fewer mistakes’ and ‘less’ pertains to singular, eg ‘less milk.’
And yes, that’s grammar pedantics, but it’s just one of the few things that’s different these days, which leads to a sense of posters being less educated than in the past. I agree that some of the typos and punctuation (the ‘S’ and ‘P’ of ‘SPAG’) is down to multitasking and use of smartphones, however the grammar mistakes can’t really be attributed to this, like the less/fewer error above.
But it’s not just that; in the past people were much more polite and supportive. They posted thought provoking ideas and it was fun to take part in debate. The practical questions related to things like dealing with colicky babies or choice of pain relief. Men having affairs, family problems.
Then everyone found MN (including the mainstream press) and the debates changed nature, they became angrier, more ‘tabloid.’ We have prostitutes saying ‘ask me anything’ and far more salacious content. It’s hard to articulate, but that’s the gist of it.
I’m sure I’ll be judged as twee and judgemental, I pointed out the grammatical error mainly because the above poster made my ‘favourite’ one. However, we are being asked what was different, and in my opinion, it was a nicer place.