We need to promote alternative web engines like Servo and libweb and browsers based on them. Many of these engines need a major push to be competent enough for daily use. Gecko is also fine - but building a new browser with it is said to be hard.
[1] https://chromium.googlesource.com/chromium/src.git/+/refs/he...
Despite all that, I would recommend only FOSS browsers with good privacy policy - because they exist.