Unless you are planning to live off the interest from your donations, how will this be possible?
1. We keep the team small enough that there's always at least 1.5 years of runway in the bank.
2. We continue fundraising actively.
I don't know if people will donate for their browser like they donate for Wikipedia, but if it's able to bring joy to people, it could be pretty sustainable. Even Mozilla takes in $10M/year in contributions.
If they didn't give their CEO $7M per year, spent money acquiring businesses like Pocket, gave up their braindead attempts at monetizing user data while simultaneously running bizarre tone-deaf "free internet" studies, and just focused on the browser and improving the development experience (is there a worse open source project than Moz??), they might fare better.