Is adding vendor prefix to border-radius relevant in 2015?

Question

css

The site is designed in compliance with HTML5 and CSS3 standards - i.e. things like the aside tag, inputs like email, etc. are used all over the place. The browser support policy is as follows: in IE 9+, and the three latest versions of the main browsers (Chrome on desktop and Android, Firefox on desktop and Android, Opera on desktop, Safari on OS X, Safari on iOS) everything should look perfect, in the rest - should be more or less convenient to use. IE 6 and 7 do not support.
Given the above, is it relevant to get rounded corners, in addition to border-radius, specify
-moz-border-radius and -webkit-border-radius?
Now - I do not add, and so far I have not seen problems with rounded corners. Am I right, or did I test badly?

Answer 1

Right. Browser support, issues and browser share can be found here:
caniuse.com/#search=border-radius

Answer 2

It doesn't matter to add it yourself. gulp does it for me.