Third-party browsers are really popular.
Most people do it because they want
to be consistent across devices.
For example, I have Chrome on my iPhone.
Because I use Chrome on my Mac, I use Chrome on my PC.
I also have, obviously, the native app Safari
that comes with my iPhone.
You will find that a lot of people
will think that a browser is either faster
and more efficient or secure.
So they will download applications for security
and to remain anonymous.