> a browser with built-in security features (both against malware and other features such as DLP, blocking/filtering/monitoring without middleboxes)
It'll be hard to outdo Google at security research and hardening
They might be doing a great job at hardening, but they don’t have a great reputation.
It's the most popular browser by far, and they actually do have a very publicized team that reports bugs to not just Chrome, but Apple and Mozilla as well. In my circles this is well respected, and personally, it inspires more confidence in the infrastructure around Chrome to me. I'd be wary of any "new" browser engines in unsafe languages.
Just that people don’t consider chrome extremely secure, it may be acceptable 99% of the time, but it doesn’t get a free pass in extreme security environments.
This doesn't mean chrome is less secure than other options, it means people are heavily incentivized to find and report security problems and google is open about issues that are found.
This makes me feel better about chrome's security, not worse, and I say this as someone who is overall kind of iffy on google these days.