On @base there are generally two categories 'consumer' and 'DeFi'. 
I want to suggest two more: zkConsumer / zkDeFi.

zkConsumer: privacy components for games, logins, NFT, off-chain compute with on-chain effects (DeAi, DePin)

zkDeFi: Privacy with DeFi.

Memory efficient ZKP at https://NovaNet.xyz

Off-chain compute triggers on-chain actions, on any device.
https://blog.icme.io/

Private Basename
zkbasename.com

Yeah but still a issue imo 

Otherwise aztec would have launched a year ago

Actually a recent US court case cleared TornadoCash and made the rules a bit more clear for privacy smart contracts.