We've taken these for granted since the beginning. Many games have these. It's just a convenient fast travel method so we don't have to run around the whole map all the time.
But who would MiHoYo be if they didn't nerd out and add in lore breadcrumbs that can progress the story? Let's start with the actual Waypoint.
Most people have checked out this description. It reads that the people of Teyvat have no clue what these things are because it's just too old. Meanwhile for our Traveler it's really clear and we use them fairly easily in game.
But that's definitely not the whole story. How about our craftable Waypoints?
Notice how it says it's convenient for Vision users. So in this case these Waypoints are being used by the people of Teyvat. You just need a Vision. And there's another point to be made here. These are powered by the Ley Lines. (And you know a 3rd point is how it messes with the Perilous Trail Event of being trapped by the Fantastic Compass when we can simply teleport out using a Waypoint haha)
I talked about this before but the Ley Lines are essentially part of the Gaia Hypothesis in Genshin. They are a living part of the planet that work with the people. And they've used them now to create something like the Waypoints to use since they can't use the existing permanent Waypoints that only the Traveler can access.
That brings me back to those Waypoints. Notice how Ley Line power isn't a part of the description. And now think about it like this. When you see one of these Waypoints for the first time what does it look like?
It's sat in the ground with a red crystal. Then you activate it and it lifts up off the ground turning blue. Like this
I have a feeling these Waypoints are Celestial devices probably made by Phanes and his shades a long time ago during the Unified Human Civilization period. But if that's the case that means they are part of the Light Realm and are therefore also powered by Light. Hence floating.
On the other hand the craftable versions come from clever humans who figured out what those things were meant to do and have started to construct something that could do the same thing only with human technology aka a Human Realm device and progress of the Human Age. The obvious weakness of it though is that they are temporary and you can only place 1 of them at a time. It could be - in a story sense - that these things tax the Ley Lines too much so planting more than 1 per allogene might be detrimental to Teyvat. At the same time it only lasts a week possibly because using the Ley Lines is too much for manmade materials to handle at the moment. One day - like after this game is over and MiHoYo is generating its profits elsewhere lol - the manmade materials might advance and be better suited to connect to and utilize them.
So why can we teleport to Domains but not Ley Line Outcrops? Same reason. The Domains notice are usually ancient and each of them has a mural with bygone symbols on them like the Triskeles. It's likely these Domains have been around since the Unified Human Civilization too and were either directly built by Phanes or the humans constructed it based on his direction. The drops we get though could still be Human Realm Artifacts because of the Ley Line trees housed inside them. Meanwhile the fact that we can't teleport to the Ley Line Outcrops suggests that Ley Lines don't naturally function as teleports also showing that the permanent Waypoints are not connected to them.
Side note: Same goes for World Bosses meanwhile the Weekly Bosses like the Shogun and Azhdaha are located in areas created by Archons. Archons are Light Realm like Phanes. And you can't teleport to Andrius since he's "dead."
Side note 2: But I think when it comes to Childe at the Golden House, the Jade Chamber and the Alcor this is just for QoL.
And that being said let us teleport to our boats MiHoYo! 
And of course there's one last kind of Waypoint. The yellow ones found in our Serenitea Pots. But these work like inside jokes because as you can read there's literally a thing about Load right there lol. We get 10 from MiHoYo. Then it explains what the Load is. If they didn't cap the Load we'd keep chucking stuff at the realm and then "Tubby" wouldn't be able to load in everything properly. Keep in mind there are over 60 million people playing this game so that's a tremendous toll on their servers. Anyway these Waypoints aren't really physical and they are powered by adepti magic. (Also the whole teapot might be powered by just the magic from Tubby. That's gotta be a ton of strain on one magical creature. Come on "Madame Ping." Isn't there a better solution?)
Tips and Tricks from a Super Casual Genshin f2p
