The current technical design of Ark would be bad for adoption imho.
From an end user standpoint,they'd need a custom wallet to support it and manage recycling vtxos to themself on a regular basis. There would not be much incentive to build competing wallets for it, so very likely there'd be 1 for some time.
And each centralized instance of Ark (the ark service provider) would take on average 120 transactions per block, and about 20kb of blockspace, so there's a maximum number of service providers that could exist.
As these service providers don't interoperate with each other it further creates adoption challenges to users recreating the same problems that exist today where say.. Venmo users cant send money directly to WeChat users. It's one of the things that makes lightning so awesome as it's an interoperable protocol with multiple server implementations.
For silo payment hubs where one wants faster transaction settlements and confidentiality, to me it makes more sense to spin up custom versions of elements (the framework for liquid) and tweak for faster block times within that federation. That frees up the block space on main chain Bitcoin and simplifies the tx operations.
