See this spoon? It's nice and round, fits a lot of soup in it and doesn't spill easily.
See this spoon? It's almond-shaped, less stable than the round one, but it gets to where it needs to, faster.
See this spoon?...

The point is, yes, there exists significant things such as security issues and compatibilities.
Beyond that, tastes start to factor in... just pick the one you like, and DON'T proselytize... if you get the whole world to use your browser, it will soon stop doing what you like it to do.
Let the browsers become specialized for different use patterns and tastes. Don't let the browser manufacturer CEOs believe they could get all the customers if they jammed in a few extra features. Make them concentrate on doing what they're good at the best they can...
by not rewarding customer-fishing.