...does that train stop right at a hill?
They couldn't animate the steelix crawling? lol
It's kind of an interesting conundrum.
Many Pokémon are designed for, and often depicted in, specific habitats. But the nature of Pokémon mandates that they be mobile in all environments. This issue is exemplified in the accommodations made surrounding a lot of water Pokémon: fish Pokémon levitate above the surface or else it would be impossible to use them on land. Even in the walking animations created for Ultra Sun & Ultra Moon (which are currently unused), most fish Pokémon simply levitate above the player and wiggle a bit as if they are swimming in the air.
But canonically, nobody expects Lumineon or Seaking to be able to fly (and let's not even get in to the fact fish Pokémon apparently can breathe on land). Yet that is how they are always depicted. Pokémon being able to float is the answer to basically all environmental and mobility questions.
Steelix has pretty much always been depicted with the ability to hover. The movement we see here is actually a much more detailed aerial movement than Steelix has ever had. But I think it will always be a little jarring to accept that if a Pokémon doesn't have legs there's a 90% chance it can float through the air without complication.
Pokémon began as a series that relied on ambiguity and suggestion to communicate its creatures, battles, and environments. Pokémon following you around the overworld, for example, raised no eyebrows or concerns when they were simply little sprites with two-frame walk cycles. Pokémon battles that took place on a plain white space, or in loosely themed grass/water/cave backgrrounds, never brought in to question the nature of size or space. You were able to use your imagination to fill in the blanks because that's just how video games worked.
But how do you tackle that in a realistic and compelling way when creating a 3D environment with object permanence? All Pokémon must be able to go anywhere. But when you can see so much of them on screen and the environments are no longer ambiguous, is it possible to depict Pokémon with any sort of logical consistency?
The question we have to consider is whether the depictions we see in Pokémon games should ever be taken literally or if they are merely
representative of what in some suggestive, abstract way.
When we see Wishiwashi floating in battle like this:
Is it really floating? Or is it just represented this way to maintain visual consistency? Are battles depicted in a literal, canonical way or are they simply a representation of what is happening in a figurative inexact way? Does it make any sense for water Pokémon, which we know for a fact live underwater, to be battling above sea-level whenever it is needed?
Steelix flying around seems like something that happens to me. Steelix is a Steel type and can learn Magnet Rise so whatever. Of course Steelix and levitate. But I do think that we just have to accept that Pokémon is not a series that will ever be able to perfectly accommodate expectations of reality. I think Pokémon will always rely on players not taking everything they see on screen literally and rely on imagination to make sense of what's going on. That's how it always worked in the beginning. It would be pretty drastic to suddenly hold Pokémon to real world conventions when it comes to terrain and space. I don't know if the game would be better that way. I'm thinking probably not, though.