I think a lot of people are overestimating the original

There's no overestimating, people just love the original movie. You may not think it's that great, which is fine because it's not for everyone, but the fans love it because it's just as enchanting today as it was when they first watched it (which is most likely several years ago).

The original is dated, fer sure. Critics of the time dubbed it only a "marginal success" -- just tripling it's budget at the box-office. (Let's see if the remake can do this). I agree that it needed a reboot -- or a continuation (Elliot DID fly off to help another kid in trouble and new-Pete certainly does fill the requirement).

But even with its flaws, the original presented a full-course meal of story, humor, morals, genuine villains you loved to boo and laugh at when their own ploys backfired. Consider the value of life-lessons offered: the true nature of friendship and love (It's Not Easy); commitment to another and defeating despair with hope (Candle on the Water); finding the joy in everyday tasks (Brazzle Dazzle Day); tolerance and consideration for others (There's Room for Everyone in this World); and the difference between loving someone and just using them (Bill of Sale). Try to tell me there are not lessons that both kids need to learn and adults need to be reminded of.

The original was far more than just pre-chewed, no-homework, puerile entertainment. If nothing else, it gave Disney Studios a good and established foundation to build off of 39 years later.

Let's see if the remake can offer this in the year 2055.

They're two very different films. The original is about a magical creature that helps out a boy who is running away from an abusive foster family. They haven't even known each other or been together for all that long. This "remake" is about a little boy who loses his parents in a car crash, wonders into the wild, and is saved and then protected for six years by a dragon. The Pete in the original was just a boy who needed a good family. The new one arguably does too, but the old Pete wasn't wild at all, just unruly because of how he had been treated. This Pete is literally a wild child, who has grown up away from humanity and civilization for most of his life.

As for the original not being great, that's entirely subjective. There are people who grew up with it, who adore it to this day, and to them, it is great. There are also people who did not grow up with it, and try to watch it as adults, and think it's corny or even stupid, for whatever reason. There are also people who watch it as an adult and find it cute, or even perhaps a few who still somehow even find it awesome.

For it's time, the original Pete's Dragon was fairly groundbreaking. It wasn't the first marriage of live actors and animation, but it was one of the first to make an entire film out of the concept, and one of the first to do it so extensively, with something like a giant dragon. So for it's time, while it does have a "corny" plot, as is typical especially for musicals, it also has a pretty significant place in the history of film and animation.

And I think the fact that the original IS a musical, also can't be ignored or underappreciated when considering it. It's not a "serious" film at all, it's a musical with many musical numbers within it. In many ways it's supposed to be silly and hokey on purpose. There really aren't musicals that are not, in some fashion, ridiculous. But seeing it as a kid, or hell, any kid probably seeing it now, the concept of an "invisible friend" who is a dragon, is pretty awesome.