Normal aligned 3DGS was already proposed earlier[1]. This seems more like an iteration on getting performance improvement by moving from the theoretical principle closer to what the hardware is already doing well and finding a sweet spot of brute amount of features, fast rasterization method and perceived image quality.

It's already noticeable that there doesn't seem to be one fits all approach. Volumetric feathered features like clouds will not profit much from triangle representation vs high visual frequency features.

There are various avenues for speeding up rendering and improving 3d performance of 3DGS.

it's surely a very interesting research space to watch.

https://arxiv.org/pdf/2410.20593

https://speedysplat.github.io/

another venue is increasing the complexity of the gradient function like applying Gabor filters

https://arxiv.org/abs/2504.11003

some many ways to adapt and extend on the 3dgs principles.

The prior paper by the authors spends more time explaining what's happening, would start there:

https://convexsplatting.github.io/

the seminal paper is still this one:

https://repo-sam.inria.fr/fungraph/3d-gaussian-splatting/

On capable devices actual downloading is even supported as an USP by most providers for offline/travel scenarios.

Besides that there are even more externalities that differentiate them:

Client and User requirements and targeted devices, therefore mass adoption and market penetration.

Downloading requires quite expensive hardware by comparison in usually quite complicated setups for a TV/like experience, it requires the user to do active file management, (which includes deleting files at some point, or buy more expensive local infrastructure) to become a mass market consumer thing, this needs to be externalized.

A streaming client is way cheaper to build and market, since doesn't need any relevant amount of non/volatile memory to speak off, that the user experience easier to sell is also quite obvious as witnessed by the golden last decade, it's only now getting tainted by encroaching advertising and platform proliferation etc.