I don't think lacking a Smash rep matters when Gen II (Pichu doesn't really count because it's just a Gen I extension), III, V don't have one either and plenty of them have a ton of marketing (Cinderace is fucking everywhere right now) but I do think you have somewhat of a point.
Gigantamaxing has nowhere near the amount of push Megas had despite being similar temporary super forms, the anime's shifted far from Galar and for the first time in the series' history, Ash's team is primarily made up from Pokemon not from the current region. Galar mons are either entirely absent or heavily sidelined from numerous of the Gen VIII spinoffs (PMD DX and Smile don't have any, Cafe has very few, New Snap has a few but none of them are used with the main Illumina gimmick). There's also the fact that most of the mainline games this gen don't even have anything to do with Galar, with two of them being Sinnoh-related more than anything else.
I think it has to do moreso with the dexcuts and GF's favorite pasttime of Kanto pandering that's really bit Galar in the ass here some than any intentional gimpage of Gen VIII. Like I said, a few Galar mons are still being plastered everywhere, but I still think you raise a genuine point.
I don't really care either because like >>48764873, Galar is fucking dogshit and easily has the worst dex in the series. Good riddance 
