You might want to consider replacing git-grep with ripgrep.
It seems you still need to enable the feature. Click your user icon in the top right -> choose "Feature preview" in the dropdown -> enable the "New Code Search and Code View" feature.
How that is not standard for the last 10 years is baffling.
Indexing/searching properly such massive data is not easy feat.
Indexing cost doesn't scale with number of searchers
Same experience here. Are there advertisement accounts posting here or something? Legitimately weird.
Ah, you need to log in to get access to the new code search!