RIP, Dan. I work with a lot of very smart people. So, I've gotten a bit used to it and don't normally find myself in awe of many people's intelligence. Dan was a person that I was absolutely in awe of. The fist time I met him very long ago (almost 20 years), he showed me code he wrote to share movies through abused DNS slaves... building a p2p network like Napser/Gnutella from the technology. No one had ever thought of such a thing. I don't think anyone else in the world knew DNS well enough to be inspired to think of it. He was so kind and friendly to everyone. It was fun to talk with him about tech/security because he had such enthusiasm and excitement... like a little kid on Christmas or a puppy. :) I learned a lot from him. I have nothing but great memories of him. I remember once when someone hacked him. He even took that in good humor and didn't let it bother him.
Possibly. There is very little to no private funding for true privacy products. I think this is one of the reasons that Proton had to initially rely on crowdfunding. Perhaps, this is because so many tech companies are stuck in the AdRev mindset where sharing customer private data is how they make their real money? If you look at the ecosystem, you see many privacy products are actually government supported either directly or indirectly. For example, the Tor Project has directly taken massive amounts of funding from the US Military and you may recall the story of how Microsoft was forced to buy Skype in order to open it up to surveillance or lose massive amounts US DoD software license contracts. Those are just two examples. But, there are really limitless cases. Trust Google? But, Google receives massive DoD/EU contracts. Apple? Same thing. Role your own? But, nearly all standard encryption and hashing algorithms were either developed by or reviewed by government funded academic researchers in the US or EU.
The way I think of the privacy ecosystem is that it makes dragnet surveillance much harder and it provides some protection if the government has specifically targeted you for data collection. So, companies/products like ProtonMail and ProtonVPN are good things. But, creating something that is 100% safe for the individual is impossible (or at best so impractical to be untenable).
I would drop Signal for that app, even if I had to pay for it.