Reproduction steps:
1. Open the attached user's project "GLTFSizeRepo.zip"
2. Open "Assets/Scenes/MemoryComparison.unity" Scene
3. Open Window > Memory Profiler
4. Build the project to Quest 2 with Vulkan and Development build enabled
5. Connect memory profiler to the Quest build
6. Connect the console to the Quest build
7. Take a capture
8. In Quest, press the left Controller Menu button and select "Cube (gltf load)"
9. Press "log texture format"
10. After the cube is loaded, take a memory capture
11. In Quest, select "Cube (builtin)"
12. Press "log texture format"
13. After the cube loaded, take a memory capture
14. Compare the memory captures
15. Note with the "Cube (gltf load)" loaded scene, the texture "Texture 2D" in the bottom right corner of the memory profiler Texture region takes 0.5 MB
16. Note with the "Cube (builtin)" loaded scene, the texture "Grid <Texture2D>" takes 256.4 KB (see attached screenshots)

Expected result: Loading texture at runtime needs 2x the memory compared to a built-in texture
Actual result: Loading texture at runtime needs 2x the memory compared to a built-in texture

Reproduces on: 2020.3.24f1, 2021.2.7f1, 2022.1.0b2
Could not test 2019.4.34f1 due to errors in the Console when downgrading the project

Reproducible on these devices:
VLNQA00415 - Oculus Quest 2 (Quest 2), OS: 10, CPU: Snapdragon XR2, GPU: Adreno 650

Not reproducible on these devices:
VLNQA00091 - Google Pixel 2 XL (Pixel 2 XL), OS: 11.0.0, CPU: Snapdragon 835 MSM8998, GPU: Adreno 540

Notes:
-Note that in the console logs, both textures are identical in every regard: same format, same size, same everything. Also, both are not in CPU memory anymore, they are only in GPU memory
-Issue is not reproducible on Windows Standalone and Android
-Reproducible only with Vulkan, because the Application does not respond with OpenGLES 3