Can we use the word raíz to depict the meaning Basic? For example, can 'el de volver a las raíces' be translated as to return to the basics ?
If you remember that it really means 'root' and try to replace it as such in your sentence it might help, because in this instance it doesn't seem to work.
Instead it fits in sentences such as:
to get to the root of, ir a la raíz (del problema, etc)
This might be more like what you are looking for:
basics, lo fundamental, esencial: we're going to concentrate on the basics, vamos a concentrarnos en lo esencial
Volver a los orígenes" o "La vuelta a los orígenes"
If you google the phrase you will see it more as "going back to the beginnings" or to the past in time.
I would stay with "volver a lo básico".
Hay que volver a los principios básicos.
Another way to say: 'to go back to the basics' volver a empezar por los principios. to get down to basics 'ir a lo importante'