[desumeku]

If bitcoin becomes a world reserve currency like maxis think it will, then in a late-stage bitcoin scenario, the main chain would have such a high demand, and thus high enough fees, that it would serve more as a settlement layer where side-chains take up the majority of user activity, which collects enough in fees to push a transaction to the 'base' bitcoin chain, using the metadata to provide cryptographic proof of its activities (to avoid fraud), kind of like ETH l2's.