I dunno. The way I remember RE2, having just played it, it actually feels shorter than what I've played of RE3 so far — and I haven't finished RE3 yet.You're actually near the end. Escaping the town is about the halfway point. It's probably about as long as RE2's B scenario. I think that is one of the reasons people don't rank it as highly. The original and 2 are both short, but they both had multiple characters/scenarios to playthrough where RE3 just has the one.
Maybe if you know what you're doing you can knock out RE3 faster, but between the increased tension/difficulty, the sprawling scale of town, all of the chaos going on, and the fact you're moving over a great distance geographically, with a persistent foe following you, makes it feel like RE3 is "grander" in scope, so to speak.
Whatever the case, I think I'll end up combining these two titles in my mind. RE2 and RE3 feel like two halves of a greater experience. It's probably the fact they're set around the same time in the same city.