Why is Ballard rent slightly cheaper than Wallingford/Fremont?

Ive been touring apartments in wallingford/fremont because ive gotten used to this area and love it, but i’m touring a couple in ballard out of curiosity because I noticed its a bit cheaper there and the unit sizes are a bit larger. Ive always felt ballard was as nice as wallingford and fremont. Is it because theres just more new apartments popping up there? I moved here last year.