Project Browser Search has slower response when compared to Quick Search and Hierarchy Search

Reproduction steps:
1. Create an empty project
2. Type something into the search of the Project Browser

Expected result: The Search result are returned after the search debouncing threshold specified in the user settings.
Actual result: There's about a 500ms delay before the Search is updated

Reproducible with: 2018.4.30f1, 2019.4.17f1, 2020.1.17f1, 2020.2.0f1, 2021.1.0a10