It’s a cliffhanger ending. And ESB was by no means wrapped up at the end. In fact, one criticism people had back in 1980, (who were no doubt unfamiliar with the old movie serial structure Lucas was emulating) was that it was only “half” a movie.
It was the escape from Hoth and the training of Luke. Han was captured while Leia, Chewy, Threepio, and the Falcon escaped. Han’s capture and Luke’s defeat and everyone’s escape is an ending. Not a happy ending, but an ending. Lando and Chewy left to find Han. And everyone who saw it should have known that there would be another one. I did and I was 10. TFA has several huge plot holes and is lacking in exposition (which there usually is too much of) and it has an ending that it goes beyond. Every other installment has an ending that we pick up years later (TESB to ROTJ is the shortest at Lucas’s timeline of 1 year). TLJ will pick up moments after TFA. New is good, but some aspects of the formula should be kept. Abrams failed to do that and failed to craft an logical story that fit with the others. All of Lucas’s failings in the PT, Abrams addressed and did better. But he failed at all the things that Lucas was good at, such as writing the overall story and having a satisfying ending. I still like the Ending to TESB to this day. It was satisfying even with the threads left hanging. I do not find TFA’s ending satisfying.