The "3D models" used in the teambuilder for Pokémon from Generations VII and before are renders that come from Pokémon Bank, which doesn't support Sword and Shield. Because of that, those pictures don't exist for the Pokémon from Generation VIII and most likely never will.
The teambuilder right now probably uses sprites because they're the best-looking option (and it would definitely look pretty silly to try to use the
animated renders from the simulator with the static Bank renders).
The important thing is that the 3D model renders you see in the teambuilder are official assets, and they simply don't
exist for Generation VIII. It's not a work in progress or something you should expect to see added; it's almost certainly just not happening.
In the interest of giving a comprehensive answer, I'm going to address a possibility, but I also want to make clear that this isn't something you should expect to happen.
It's
technically possible for a fan to go through Sword and Shield's models manually to render them in a more similar style - the amazing modelers from the
CAP 3D modeling project have established a system for renders in this style for models of their own creation, while a 3D modeler here on Smogon has expressed interest in
rendering the Generation VIII Pokémon in the style of Generation VII for battles but has been halted by
difficulty parsing the animations of the models, which are necessary to make this possible in any reasonable amount of time.
However, even once those animations are available, re-rendering every model takes time and effort, and this is just one person offering to help.
Doubling that workload by adding teambuilder renders on top of that - especially when the teambuilder is perfectly serviceable as it is and the priority is on making battles look nice if anything - seems like too much to ask and for too little gain, so I would not expect this to happen at all. The person who offered to render their idle animations decided that of their own volition; no one is entitled to ask any more of them.
Aside from that, please try to be more patient. The first time someone answered you, you made a backhanded comment about how long you had waited even as you thanked them (and three hours isn't long at all...), and now you sound pretty sarcastic and passive aggressive. People aren't going to want to help you when you act like that.
Edit: I just looked at the teambuilder and realized what you were asking, so I changed my post to a proper answer.
