Email is good example of something that lasted. I think piecing it apart in more detail picking another few cases could let me clarify and solidify my arguments

Email is good example of something that lasted. I think piecing it apart in more detail picking another few cases could let me clarify and solidify my arguments but like you HN is probably not the place for a detailed analysis. Long term, I would hope that if Signal gets large enough market-share and stabilizes they would make the signal protocol federated.