Let's stop the craziness of 50 different programming languages which all bundle slightly different sets of features. Can't we just put all the features in one language?
The reason to use one icon set on a web page is that the icons look good together. Putting a bunch of different icon styles in one set defeats this. A good designer has the skills to bust out Sketch and make another icon in the same style if they need it, and then contribute it back to the set for consideration.
If you're not able to do this, there's always http://icomoon.io/app/ which lets you bundle icons from different sets into one font.
The reason to use one icon set on a web page is that the icons look good together. Putting a bunch of different icon styles in one set defeats this. A good designer has the skills to bust out Sketch and make another icon in the same style if they need it, and then contribute it back to the set for consideration.
If you're not able to do this, there's always http://icomoon.io/app/ which lets you bundle icons from different sets into one font.