I would add the SPS in addition to witness rewards, but my next move would be to create a top quality suite of tools, SDKs, documentation, etc for various kinds of popular "dApps". So for example, if someone wants to build a blockchain-based game, they just grab the Steem Game SDK and it handles everything they need to build a game on the Steem blockchain - blockchain interaction, integration with tools like steemconnect/keychain, payments, token/NFT creation & management, decentralized marketplace functionality, RC/SP delegation, etc. Same for other popular types of dapps.

Then we go out and do whatever we can to get as many apps built on the Steem platform as possible, which should be a whole lot easier if we have great tools, docs, and support. Every app on the platform will need to hold enough Steem Power to support their user base through RC delegation, so if we're even remotely successful in getting some serious apps on here the demand for STEEM should quickly be able to outpace the new supply (due to significantly reduced inflation).