Vivaldi's business model is primarily revenue from deals with search providers. they don't exclusively get money from Google, they get money from all their search partners, including Google.

Brave is into crypto scams and advertising scams, so I guess you're right there. Their revenue is also tiny.

The rest aren't what I'd call "real" browsers, most don't have the same level of functionality and compatibility as Chrome, Firefox, Safari, Edge... Servo for example is literally just the rendering engine Firefox gave up on.

Do Brave and Vivaldi fund actual browser (engine) development, or are they just using open source Chromium (as they're able to)?

Konqueror and Epiphany are Webkit based, so presumably benefit from Apple's funding of Webkit.

Ladybird and Servo aren't real browsers yet, and have so far been funded by grants which doesn't seem to be long-term stable.

Brave is just Chrome in a trench coat. I am pretty sure all the others are based on something else or are not actually a fully robust browser.