One of the main reasons it's so popular is that is preserves shape, angle and north is always up. This means you can create a tiling map server and use the same tiles at all scales.

It is possible, but not trivial:

https://www.vis4.net/blog/posts/no-more-mercator-tiles/ (comments are also informative, particularly Tom MacWright's)

https://mapzen.com/blog/escape-from-mercator/