We find Bitcoin offers superior performance, security, and cost-effectiveness, due to its skillfully constructed fundamental design.
The former two are volatile and ephemeral, meaning they are reset when the EVM starts to run a new contract call.
As a consequence, each contract can depend on another one since they may read/write the same storage.
Ethereum can be considered to be a single-threaded machine, which is limited by the capacity of that machine.
In Bitcoin, smart contracts reside in the so-called Unspent Transaction Outputs to process smart contracts that is also stack based.
It is horizontally scalable and can scale infinitely by simply adding any number of machines to the existing pool.
Ethereum, by contrast, has been stuck at a mere 15 tps for years, with a history of repeated broken promises and no improvement in sight.
Also they can tested accurately off chain since they behave the same, regardless of how, when, and where they are executed.
Due to this vulnerable design choice, it has been plagued by tens, if not hundreds, types of attacks, resulting in loss of hundreds of millions of dollars.
Given its 5-year head start, it is no surprise that the ecosystem on Ethereum is more mature today, in terms of developer tools, libraries, and applications.