What is considered a "long" campaign?

So I recently saw someone mention an interest in playing in a long campaign, which they then labeled as 30-40 sessions. To me that's much closer to what I'd call a short campaign. I mean, I'm running a game right now that's closing in on its 100th session.

I guess it's not terribly surprising that this is a highly subjective thing, but I'm curious if there is a consensus out there.

I'm particularly curious because I see people ask things like "what's good for a long form campaign" or "game x is only good for short campaigns" and like... if 'long form' and 'short form' mean different things to different people, questions and comments loke that without further specification will probably not produce valuable responses or give valuable feedback, right?