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.
Same, having competitors to Android and iOS would be great.
The are some alternatives out there. Calling them competitive might be a stretch though.
I had a Windows Phone (NOT the older Windows Mobile) for a while back around 2011 thanks to my job as a multi-platform mobile developer. I loved that phone and the OS and developing apps for it was a lot easier and faster than for Android or iOS. I was surprised at how quickly Microsoft kicked the whole thing to the curb.
Nokia Lumia 700 in bright blue was stunning! I really liked it, the tiles were different and it felt funky. Pity they abandoned the project.
There's a Linux phone, but I've heard it is a beautiful mess.