It would either completely obsolete ranged weapons as, you know, a form of ranged attack, OR be a massive nerf to the spells, depending on how it's done. Additionally, it's generally not needed in most games.
If a spell has 25ft + 5ft/2lv, then a level 4 caster already has 35ft range, which is enough to cover most engagements so long as you don't attempt to stay safely away and snipe... at least not till higher levels.
If a spell has 100ft + 10ft/lv, It's already comparable to the first increment of longbows and other ranged weapons, and will quickly equate their second, and eventually third and fourth increments as well. If using map combat, you'll rarely even get to fully use the second increment of any long-ranged weapon
A "long range" spell has perfect accuracy out to an absolute minimum of what, 440ft? that's "out of range" for the majority of throwing weapon users, pistoleers with a Distance weapon, and more in the vicinity of siege weapons showing accuracy problems by the time you actually know/cast spells with 'Long Range'.
If that fireball had ten long range increments, you can forget about fielding armies made of sword and spear users.