I also wonder if GitHub Discussions was also a (minor) contributing factor to the decline. I recall myself using GitHub Discussions more and more when it came to repo specific issues.
I believe Walmart has a deal[1] with Apple to sell[2] M1 MacBook Airs. This has been the case for a year or so, so I don't think it's old stock. They have been in stock for since that date, and slowly getting cheaper.