I run Brave on Ubuntu Noble where it is installed via snap. I have the latest version 1.75.180 Chromium: 133.0.6943.126 (Official Build) (64-bit) as of today.
Startup times are horrenduous since the beginning of the week (shortly after the change was made to allow tab groups in the bookmarks bar). We are talking about 1 hour running at 100% on a single core.
My extensions have not changed since last week. Let me know what other information I can provide to zoom in on this.
In your situation, the first thing I would suggest testing is whether or not the Beta Build of the browser runs just as slowly. The Beta will install as a separate browser and you’re welcome to uninstall it after testing.
This will help us confirm if the issue is with Brave itself or if it’s something contained within your browser profile.