Mozilla has been compromised and cannot be trusted.
Google is untrustworthy and even open-source Chromium is suspect (has downloaded binary blobs).
Brave seems nice but started out it's business model by blocking ads, and replacing them. Which is sketchy.
Opera seems nice, but it's proprietary and I would feel more comfortable using something open-source.
Vivaldi seems to be bloated and is also proprietary.
Alternatives based on Firefox or Chromium seem less likely to keep up with security and often have unclear motives.
I'm leaning towards Brave right now, but I must say I'm not pleased with the options.