What makes a pane successful basically comes down to money. Airlines are a business after all. They want to make a quid and it is a very fine line.
For instance, I will provide an example. The Airbus A380. Looks to be a fantastic machine. A lot of innovation and technology, plus massive capacity and range.
Do the airlines like the A380? The answer to that question is NO. QANTAS was a launch customer. QANTAS now believe that the A380 was one of the biggest mistakes in their history. They now want to get rid of them but can't sell them. So they could end up being moth balled eventually in the Nevada Desert Graveyard.
Reason why they don't like the A380 isn't because it isn't a good aircraft, but because they need a lot of bums on seats to turn a profit and more often than not, they are losing money. So the aircraft has become a white elephant money pit. Emirates are the same and so too so many other A380 operators. Production of the aircraft has ceased because no one wants to buy an A380.
Is the A380 better than the B747. Answer to that is NO. The B747 was a very successful aircraft over 4 decades. The B747 is an icon. A380 is a bit of a failed project.
The high capacity sector will be dominated between the B777, B787, A330, A350 (that's a little ripper) and the the next gen B797.
The medium haul sector will be dominated between the A320 family and the B737 family.