How to reproduce:
1. Open the attached “[SlowdownPackage.unitypackage|https://editorbugs.unity3d.com/api/v1.0/attachments/f04abef3-1dd7-4761-bbfd-4c0a75162741/SlowdownPackage.unitypackage]”
2. File → Build Settings and change Platform to WebGL and check Development Build
3. Click Build
4. Run the WebGL build on a local server (python http.server was used in testing)
5. Connect to the server through a mobile device browser, start quickly tapping the screen, and observe

Expected result: The performance doesn’t drop and the project runs smoothly.
Actual result: The performance drops and the project starts to lag with each tap.

Reproducible with: 2022.2.3f1, 2023.1.0b2 (Only on iPhone), 2023.2.0a1, 6000.0.15f1
Could not test with: 2020.3.44f1 (Missing features in a package), 2021.3.17f1 (Errors in packages, building fails)

Reproducible on: macOS 13.2 (Intel),

Reproducible on devices:
Samsung M34, A53 (both with Mali GPU's) - [~animesh.jha] 
VLNQA00277, Asus ROG Phone (ASUS_Z01QD), Android 9, CPU: NOT FOUND, GPU: Adreno (TM) 630
VLNQA00334, Xiaomi Mi A3 (Mi A3), Android 11, CPU: Snapdragon 665 SM6125, GPU: Adreno (TM) 610
VLNQA00134, Samsung Galaxy S8 (SM-G950F), Android 9, CPU: Exynos 9 Octa 8895, GPU: Mali-G71
VLNQA00331, Huawei P20 lite (ANE-LX1), Android 9, CPU: HiSilicon Kirin 659, GPU: Mali-T830
iPhone XR, iOS 16.2, Safari

Not reproducible on: Samsung Note 9 (Adreno 630) - [~animesh.jha] 

*Notes:*
- The performance drops only when the screen is tapped. The severity of the drop depends on the number of taps done in a short time. Google browser was used on Android devices.
- The performance difference between Adreno and Mali is 50% almost, which is a lot. - by [~animesh.jha]