Self-plug but my indie conferences [0] promote software that respect the user's quality of experience. One of my favorite presentations that we've featured is SerenityOS (including their open-source browser) which made headlines at the time. [1]
On Gnome, "Web".
On macOS, Safari may not pass your "non-corporate" requirement, but it's spiritually non-corporate, and functionally "just a browser". It's also wicked fast and extremely light on your resources.
On many platforms, "ungoogled-chromium" may satisfy your needs. It's under the name "eloston-chromium" in many repos. https://github.com/ungoogled-software/ungoogled-chromium
https://html5test.com/results/desktop.html
Looks like its the worst. Unless you have something proving otherwise. Till then I'll assume all your facts are bullshit.
I'm trying to ungoogle and switched to Vivaldi without enough research. Its a really nice browser and I really like the community around it (like their Mastodon service), but I basically jumped from one corporation's browser to another.
Seems to me that businesses operate within an incentive structure that will always encourage them to take maximum advantage of users and do anti-user things no matter what their original goals were. The non-corporate part is key imo (see Canonical, Mozilla now etc.)