you're both wrong.
of course everyone has a limit to their range but i believe that some people say that because thye want to justify their lack of ability.
3 years ago i was in your same position... my range was from e2 to f4... i sang every day in my commute to school/work/whereever i was going and read books and listened to professionals....
all of it was crap!
the only thing taht counted was the first thing i mentioned.... "i sang every day"....
singing is nothing you can think about and learn how to make your throat go a certain way by THINKING about it or at least not in contemporary music. its figuring out what works and what doesnt by trial and error.
i've gone through a lot of phases where i couldnt sing at all for about a week because i was singing imporperly and stressing too much. so i adjusted from there. and tried to figure it out.
you learn how to sing different notes by learning how to access different registers within another register.
i learned quickly to expand my vocal range up to an A-
B range... which those of you who are trying to expand your vocal range... even expanding it 1 or 2 notes is exciting.
after a lot of practice and figuring thigns out on my own and not listening to "professionals" or "vocal instructors"..
im maxing out at a G above tenor C... G5 (?) the highest G on a guitar in chest voice.
however i did notice i lost some of my low range.
went from E2- F4... to G2 - G5 ... i'll take it