Just a few examples that I remember from my time here:
MyCryptoMixer.com ran a campaign for 40+ weeks but ultimately failed due to unknown reasons.
Bitamp Web Wallet ran a campaign for 28 weeks during 2020/21. The project is practically dead now as far as I can see.
Go-Overt ran a campaign for 16 weeks but failed.
YOLOdice casino campaigned for over two years but ultimately closed its doors.
MyCryptoMixer were had a serious accusation toward them and they comes up on the wrong timing because Chipmixer were dominating in that time. Go Overt were same, they can't compete against Chipmixer.
Bitamp website is still active, I can access it.
I was a participant of Yolodice, honestly they're still making profit until they closed their website because they have an investment bankroll and the graph were healthy.
There were two quite long campaign about wallet niche, they're
OWNR and
Wasabi wallet.
Although I don't have any proof, I don't see any campaign about wallet niche become successful

most of campaign about exchange niche were either failed or not giving any good impact, except
Kucoin