I think what gets me about the concept of "solarpunk" specifically is that it's so much worse than steampunk or dieselpunk or whatever because it's entirely shallow and largely carried by "this is morally correct"
as much as I find steampunk bland and annoying, the seminal piece of steampunk art isn't a chobani commercial
you absolutely could do an interesting setting with widespread embracing of solar power, but you'd first have to deal with the uncomfortable parts of it, like that solar power isn't actually the most environmentally friendly power source, or that a solar utopia inherently requires rare earth metal mining
and just because they're both equally manufactured and people keep pairing the two, I'll swing at the hornet's nest a little harder
"hopepunk" as a genre is fake because it's characterised by being an inversion of "grimdark", a genre which also does not exist
Hopecore and solar punk are made by and for people that like corporate memphis.
