Yeah, the expectations of games - not only in size, quality of animation, graphics, etc - caused budgets to swell. In the late 90's, we were caught up in that technology race - where things just kept advancing so quickly, and people always wanted to be at the forefront of technology.
I think we've reached a plateau now, though - as computers have become so commonplace, we've almost settled into a more decent pace. We're not always trying for the latest in technology - there's still development, but it's not a fever pitch.
Adventure games suffered in those feverish days - but I think with a new stability in the market, they'll find their place again.
Bt