I somewhat agree with you, but not entirely. With a GM that is intimately familiar with the world, an effective and well-made story can be made without all of the elements you outlined.You are, of course, entirely correct in this view and assessment of DragonLance.
But there is a reason for that and how that element emerges in the narrative of the tale. DragonLance is not simply a story that takes place in a setting, it is a story that involves characters with pre-existing relationships. It is "the Star Wars of D&D" because of the familial bloodlines and their pre-existing relationships. DragonLance is not just a story about the setting or the bad guys. It's a story about the good guys, in a way that no other Adv Path really has been since. And that's the problem.
There are a lot of gamers -- the large if not overwhelming majority of which -- find the idea of playing a pre-generated character to be anathema to their roleplaying experience. I cannot disagree with them about that. They are not wrong.
There is a reason that the romance and tragedy of DL can't be repeated without those pre-existing relationships. It's the lifeblood of the story; it is the bathwater you are trying to throw out. In order for it to work at its best, you need it. Yes, even if you hate it.
You don't have to do it with the pre-gens, but you are going to throw out that romance and tragedy without it. That's the part you need to square with and stop hand-waving it all away as if it doesn't matter. It does matter. It matters a lot.
For new players? The pre-gens work really well. The problem comes when they have read the novels and are making those choices; or FAR worse, when the DM has read the novels and is trying to force the PCs to make those choices. But if you stay away from those easy to avoid pitfalls? It works brilliantly for someone coming at it tabula rasa.
And that isn't us.
However, there are millions of customers who are not us. And it's been 37 years. Most new players? They haven't read them. At all.
No, it's not going to work for the vast majority of people reading this thread. But here's the thing: that's okay. The vast majority of us here are doddering old grognards. We are not the players to focus on. We're not the market for this 5e product.
We can, however, be DMs for it to those who are noobs, if we are lucky enough to find such an unsuspecting group to unleash it upon.
And if not? That's okay too. It's not about you; it's not about us. It's about the people who aren't reading this thread.
For example...I ran a retelling of the War of the Lance with a different group of characters. Essentially, I ran a what-if scenario that asked, "What if the Heroes of the Lance never showed up at the Inn of the Last Home on that fateful day?" And, not to toot my own horn, I think it went very well. None of the characters started off with those familial aspects, nor the romance. However, the epic tone, the world-building and lore of the world, all melded to create a very enjoyable story that my group still talks about.
Then again, I did change the story enough to make it my own. I think that is, in essence, what 5e Dragonlance needs to empower the DMs to do. How do you make it your world? How do you add that epic tone?