Synapse already showed the failure mode: the API layer can outrun the ledger/control layer, and stablecoins make that 24/7 instead of business-hours ACH. With ~$314B of stables outstanding and USDT/USDC still dominating, sponsor banks that package mint/redeem, Travel Rule, sanctions screening, card settlement, and Tempo-style memos can become the distribution layer while Circle/Tether become balance-sheet suppliers. The margin lands in reconciliation, compliance, and yield routing to tokenized MMFs/Aave/Morpho more than in another branded wallet.

Top comment by @Benthic