How do wallet developers make their money? I'm not referring to the open-source bitcoin only wallets which their funding is from donations and personal help. I'm referring to the rate at which almost all centralized exchanges out there now have their own personal wallet, which they claim is none custodians but its close source, so I'm asking how they are really making money from owning these wallets. To the best of my knowledge, transaction fee don't go to wallet owners, or are their earning solely dependent on the staking as most of them are multiple chain wallet and support staking together with bridging
The rapid growth of new wallets, especially how centralized exchanges are owning there, have left a lot of unanswered questions in my head.
No one does anything without benefits, so developers have some way to make money from their wallet. Centralised exchanges want to maintain their dominance. That's one of their benefits; also, they have financial benefits as well. It's true they aren't earning from the transaction from their wallet, but there are many ways to earn; I will describe them shortly.
Even if you ask this question, you may get some answers. A closed-source wallet even could place banners on its wallet. They could feature anything like dApps or other crypto elements. You can swap from there, and they could earn commission from there as well. They also partner with many aggregators and offer fiat-crypto swaps, from which they also earn. So I want to say they definitely have some benefits behind launching their wallets.