If everyone can use magic to some degree than your going to wind up with a world like Saga Frontier 2 where magic is ubiquitous and the inability to use it
is considered a disability.
In such a world a lot of the technological development is going to be centered around facilitating the use of magic,and filling in the gaps that magic can't economically.
Wizard or Mage would just be a title for the prodigies that are actually good at using magic.
For comparison, anyone barring disability can engage in athletics yet out of the population how many have the physicality to become professional athletes?
Out of those with the physicality f\how many have both the inclination and dedication?
In a world of guns and explosives what role do battle-mages have?
First they'd be Force Multipliers called in as special use troops and not the bulk of an army,t here roles would very greatly according to ability.
But those among them who were combatants instead of playing a logistics&support or espionage role would act as highly versatile artillery.
If much of the technological base is magical, then advancement will be heavily influenced by the ease at which enchanted items can be produced.
And what exactly magic can do in your world is going to be the biggest factor, if we assume the basic fantasy rpg power set as well as a fairly economical means
of enchantment then...
Your setting isn't going to be late 19th to early 20th centenary for very long, it have even skip from medieval directly to space faring.