Today 10 years ago I went to Poland to buy a Phone with pre installed #Firefox OS on. The Phone was a Alcatel One, so very shitty. Two years later I installed Firefox OS on my Nexus 5 instead.
It was a very good concept, but sadly rolled out on too shitty hardware so it never caught on.
I also have a KaiOS phone, to have a dumb phone with Whatsapp. Did you come from the /r/dumbphones community too? ;-)
Nope. I bought it years ago as my spare phone for emergency use.