From their blog:

Empowered by Coinbase: Base makes it easy to build decentralized apps with access to Coinbase’s products, users, and tools. Seamless Coinbase product integrations, easy fiat onramps, and powerful acquisition tools enable developers to serve the 110M+ verified users and to access $80B assets on platform in the Coinbase ecosystem.

Coinbase officially entering the ring. Financially, there's too much money left on the table by not doing this. "Diversifying" and expanding into becoming a major player on the protocol level is the logical, proven way to expand Coinbase's presence.

Will be interesting to see if we enter the following equilibrium for L2s/sidechains:

• US-based developers build on Base -- primarily due to Coinbase's distribution and their seamless integration into Base.

• Permissionless builders build on Optimism/Arbitrium -- classic example of a credibly neutral web3 native team (especially once sequencers are fully decentralized).

• Developing countries (mainly Southeast Asia) build on BNB -- already have a major presence in countries such as Vietnam and Thailand.

Obviously, deploying to a given chain is not mutually exclusive (all EVM-compatible), but it seems that the apps will optimize for deployment on their intended chain.