I recently had cause to sign in to the Google Cloud console (not BigQuery specifically) and found it unusable on Firefox. It pegged a core at 100% and consumed memory at a prodigious rate. Basic UI actions were painfully slow.

I killed the tab and tried it in Chromium where the UI was... not snappy, but in range for my expectations of a heavyweight frontend.

I use it all the time on multiple platforms and it is a DOG on anything but Chrome/Chromium. We have 30+ datasets each with many tables/views/functions etc tho so that could be part of the issue.

Same thing will happen in the billing portal or really any experience but I notice it the most in BQ.