I don’t know what you’re implying and your question isn’t asked in good faith. What is your definition of “the long run”? Because apparently seven years is not what you consider long enough. It’s apparently also “clear” that optional donation doesn’t work, but you don’t feel any need to elaborate on why that is clear, or what examples you have that Signal is failing to hire competent engineers or to “innovate”, whatever that means.

You know Signal has raised 50 million dollars when it started, right? And people don't give millions without any expectation of return. Whatsapp had been ad free for longer, but that doesn't mean its plan is just to not earn any revenue.

> people don't give millions without any expectation of return

Perhaps you're not aware but Signal is developed by the Signal Technology Foundation, which is an American non-profit organization. So yes, people do "give millions without any expectation of return".

If the $50M USD you're referring to is the money donated by WhatsApp co-founder Brian Acton, it was definitely not given with the expectation of returns, as donations rarely are.

Elon Musk has also confirmed publically that he has donated to Signal:

https://bird.trom.tf/elonmusk/status/1348506592518438914 (mirror)

https://nitter.kavin.rocks/elonmusk/status/13485065925184389... (mirror)