Even if you want to freehand everything you should use 3D to check what the scaling and convergence amount should look like so you know in the future.
Learning freehand perspective is only a small part of being able to draw backgrounds, you need to know what stuff looks like when it is scaled correctly and within the cone of vision vs experiencing distortion from a wide angle lens.
Studying the perspective of photo ref, cinematography from film screenshots and 3D is a huge help for training you to "see" environments and intuitively understand scaling and convergence.
There aren't really all the many angles you can draw stuff from that look good. Eventually you will just be drawing the same perspective setups from memory because they work and it will become part of your style.