How to reproduce:
1. Open the user-supplied Unity project
2. Make sure in the Project Settings > Graphics tab that URP Asset is the used render pipeline
3. Build for iOS and open the Xcode project
4. In Xcode, navigate to Product > Scheme > Edit Scheme...
5. Make sure GPU Frame Capture is set to the used graphics API (Metal or OpenGLES)
6. Launch the app on an iOS device, Capture GPU Frame (Photo apparatus icon)
7. Observe the GPU Frame Time value

Expected result: the performance of MSAA x2 on URP is not negatively impacted very much in comparison
Actual result: MSAA x2 on URP is up to twice as taxing as the Built-in Render Pipeline using MSAA x2 (~4 ms Frame Time vs. ~1.3 ms Frame Time on VLNQA00160)

Reproducible with:
7.0.0 (2019.3.0a10)
7.2.0 (2019.3.0f6)
7.3.1 (2019.3.10f1)
8.0.1 (2020.2.0a7)
9.0.0-preview.14 (2020.2.0a7)

Could not test with: 2017.4, 2018.4 due to URP being available since 2019.3

Reproduces on:
VLNQA00160 iPhone 6S iOS 13.3.1
VLNQA00249 iPhone 6 iOS 12.4.2

Unity 2020.2.0a7 with URP 9.0.0-preview.14:
URP MSAA x2 on Metal GPU Frame Time: ~4 ms
URP MSAA x2 on OpenGLES3 GPU Frame Time: ~3 ms
URP MSAA x2 on OpenGLES2 GPU Frame Time: ~3 ms
Built-in RP MSAA x2 on Metal GPU Frame Time: ~1.5 ms
Built-in RP MSAA x2 on OpenGLES3 GPU Frame Time: ~1.3 ms
Built-in RP MSAA x2 on OpenGLES2 GPU Frame Time: ~1.3 ms