I think Epicdan nailed it. Every lens has a purpose. There is no one right answer.
The "you" in the examples below is used in a generic sense.
If you are shooting low light action on a soccer pitch or football field, switching primes will not work very well. A fast zoom is probably best.
If you are on a hike in dusty conditions and shooting landscapes, overall range is a consideration. How often do you want to expose the inner parts of the camera and how many lenses plus tripod plus water plus food do you want to carry?
If you are in a studio shooting at pre determined distances, I doubt you can beat a fast prime.
... There are so many more scenarios. No need to list more of them.
To me, it's a balance of cost, the settings in which one shoots, the desired results, and personal preferences.
Dimitris, can you afford to keep the 24-70 while you try the 24-120 (or 24-85) and asses if the IQ measures up to your expectations and then decide on the need for primes and whether to sell the 24-70?