How is the experience of using those search engines with their own indexes? At quick glance, brave seems adequate, but would like to know what others think.

Why not both, Google engineers and Google execs? If you've ever looked at how Google engineers talk on the Linux kernel mailing lists, and their code in android internals, they tend to have a "we know best" or holier than thou attitude.

I wouldn't be surprised to see this trash also coming from the same kind of Google developers who act like that.