Earlier quoted context omitted.
In case the OP wanted to know exactly how Brave's adblock is different from uBlock Origin instead of a link to the marketing page with links to other things like cryptocurrencies: Brave's browser claims a speedup over AdBlock plus, but was inspired by UBO, so the performance is fairly similar, but is baked into the browser instead of being an extension. > We therefore rebuilt our ad-blocker taking inspiration from uB…
It's also written in Rust for performance.
Also just so you know, Brave isn't "written" in Rust alone, it is a big software with a lot of parts, including but not limited to a rendering engine, a JS VM and a WASM engine.
The Rust part at most (unconfirmed) would be the glue that connects them together, and I doubt that's where the bottleneck is for most browsers.