goBILDA, Actobotics, Tetrix: How to Choose, How to Use 

That's a fair question, although REV is notably an extrusion-based system, unlike these channel based systems

@@quinn.mcginley do you think I can use any of the starter kits only to build a advanced robot even outside of FTC. What do you think I should get other then the starter kit to make advanced robots

REV uses plastic bushings, plastic brackets, and 5mm axles, which are flimsy, higher friction, and prone to binding. It has channels, but they're not as easy to use as goBILDA channels because they don't have such a grid pattern. It has some face mount bearing blocks, but they're nowhere near as nice and compact and easy to use as goBILDA's variety of flanged bearings and pillow blocks. It has t-slot extrusion, which is useful for its versatility, but goBILDA has similar extrusion that is bigger, stronger, and easier to mount on the ends. Since good REV parts like Ultraplanetary gearboxes and mecanum wheels and REV hubs are easily compatible with goBILDA anyway, why not just use goBILDA?

wrong actobotics is a descent of lego christ himself making it the best build system known to man

Agreed, Tetrix is looked down upon but the greatest thinkers know how to use it 😎 It really doesn't have that much problems as people say it does, maybe for mounting things together but the big holes are easily usable for custom adjustments in which you can set your mounting to.