Major systems replacements and that sort of thing are budgeted in the capital reserve. The operating budget is just that... operating.
Yes, but day to day maintenance is part of the dues. And older buildings generally need more (and more expensive) day to day maintenance.
The capital reserve handles things like scheduled renovations and updates.
But if the new building needs a plumber for a burst pipe only 3 times per year, and the older building needs to call a plumber for burst pipes 300 times per year.... It's going to translate to higher MFs for the older building.