This question already has an answer here:
- Do I really need a fast 50mm lens? 8 answers
Do I need 50mm lens If I have ef 24-105mm f/4l is usm lens for canon 6d? What should be my next lens? I mostly interested in landscapes.
If you are mostly interested in landscapes, spend your money on a good tripod, if you don't already have one. Then spend your time shooting, traveling, etc. If when you find yourself limited by your lens, then you will know what to buy.
Shoot, critique, rinse, repeat.
If you need a lens to do something that a 50mm prime lens can do that the EF 24-105mm f/4 L IS can't do then yes, you need a 50mm lens.
Until you can explain exactly what it is you need the 50mm prime to do that the EF 24-105mm f/4 L IS can't do, no you don't yet need a 50mm lens.