Why are there no drivers for Roland Fantom G Windows 10? I would like to upgrade from Sonar X2 2 sonar Platinum but now I'm not sure if it's worth it.

This isn't really the right place to ask. Cakewalk is not owned by Roland anymore, Roland sold them to Gibson Guitars a few years ago. That aside, Cakewalk never did drivers for Roland hardware. You would need to ask Roland about drivers.
 
That aside, none of that effects if getting Platinum is worth it or not. Platinum functions fine in Windows 7 and 8 so if you were going to stick with one of those it would still work, and its features are not related to any hardware you have.

I am assuming this is a question about part of VS700 series interface. Either way, it is a Roland issue. Cakewalk does not write hardware drivers.

Some users have gotten it to work here: http://forums.rolandclan.com/viewtopic.php?f=3&t=50840

navarro.hicks
Some users have gotten it to work here: http://forums.rolandclan.com/viewtopic.php?f=3&t=50840

either this or this here should help to get your Roland device running under win10 - you might have to temporarily disable driver signing as described in the thread

I'll try the workaround. Thanks