I'm coming up on 10 years as a very satisfied paying member of Fastmail's service. I just re-upped for another 5 years for my Enhanced account. IMO, I'm happy to pay for a service that I use all day/ every day.
There's so much more in this world to be upset about, email is not one of them for me.
Also, I'm hoping that at least one of the disgruntled "soon to be former" fastmail users will vacate an alias that I want