Right. Bitcoin transactions can be submitted by Coinbase or any other company that does KYC, etc. But, with a bit of effort, you can self-custody and submit privately. Same with Lightning -- you can spin up an Alby Hub, on your own machine, open your own channels, etc. -- thousands of people do this. Just With Spark, you cannot submit a transaction privately -- you don't have that option. You need to use their API. There's no way to interact with the protocol in a private manner. Again, maybe that's fine for certain kinds of users.