The easy answer to the bus "efficiency" issue is that the number of busses needed to match the throughput of the gondola would be absurd...think in the neighborhood of five or six busses loaded and dispatched every ten minutes. That number is assuming the gondola is UNDER the same capacity that other similar systems use.
Before you start saying..."well...hire more busses and drivers, so you can flex". You also need support systems to utilize them...this means, more standing lots for empty busses to wait/full bus unload, more bus load platforms (you aren't turning a bus around every 1.5-2 minutes...just not possible, or at the best extremely unlikely) and things like more traffic lanes/increased congestion to add in all those busses. Remember...its not just the five busses you see at the park, based on travel times, there are likely about 15-20 busses en route to their destination each way, so lets be conservative...30 busses total on the road, in addition to the ones waiting to load unload, so about 40 busses...per route...yep. Per Route. If you want to keep that efficiency level up for the hotels you serve, you would need this running for everything. So lets be conservative and say to service the hotels at the same lowest level theoretical of the gondolas, you would need about 80-90 busses. Im not even joking. If you say "nuh uh...they don't need those busses going both ways...". Yeah, you do. At park close, the bus would drop at the resort and likely need to make a return trip with NO guests...making it a dead trip and pure waste.
Now you are likely asking, "But Bender...the gondola is dumb, because it still takes time and isn't flexible. You can always tae those busses off the routes and move them around." Well...yes, but outside peak times, what do you do with your 80 extra busses and drivers? The advantage of the gondola is that the cost to operate it with one person on the system vs 2000 is exactly the same. It scales up to its maximum with no loss in efficiency. What you lose in route flexibility, you gain...big time, in scale and operational costs. If you need three Cast Members per Gondola station, you need three cast members.
Basically, the efficiency of the gondola has a definite limit, just like anything, but in order to match it, the bus system would need to be ludicrously efficient and insanely expensive.
There are other issues at play here, too...like having that many busses would actually cause overall efficiency to plummet (there is a reason for the number of monorails per beam...ay more and the whole system starts a cascade failure)..but that's for the next story. Im just assuming the bus is hyper efficient and the gondolas are running at their lowest standard operational efficiency.