[Nextgrid]

The problem is less about how known the protocol is and more about whether the platform owner uses its influence to prevent others from implementing said protocol.

Even a completely obscure protocol can be reverse-engineered given enough time - in fact if you search on GitHub you can already find a lot of client libraries for proprietary services.

The problem is that at the moment the platform owners intentionally detect usage of these alternative clients and ban their users or abuse laws such as copyright to block their development & usage.