I wouldn't call it "arbitrary" if it's one person spamming the blockchain for so long. The reason I still think it's one person is because of the massive numbers of similar transactions that keep flooding the blockchain. If fees aren't enough to deter spammers, I'd like to bring back the "coin days destroyed" priority mechanism. But it's going to be difficult to get miners on board if it means less profit.
As I said, I don't know "all the data", is it indeed only one entity doing all the spam?!
But at the end, it goes to miners (and, as you said, let's not count on them because they're in only for the money) and maybe to community too.
I guess that the community can do wonders - from switching to a "filter on" wallet/node to actually putting pressure/convince the devs to this direction. But... is the community convinced? Imho it's not. Imho if we want to go on this direction we may need to start with properly exposing the wallets (and hopefully entities too) that are responsible for all this spammy mess.
It feels soooo like in the winter of 2017/2018...
I checked and I saw no rare satoshi in this address
So it's not Ordinals related after all? Interesting...