Phoronix compared the performance of Firefox and Chrome on a Linux desktop. They used recent versions (at default settings) of both browsers on an Intel Core i9 13900K “Raptor Lake” system with Radeon RX 6700XT graphics.
They concluded that “Google Chrome performs much better overall than Mozilla Firefox".
One area where Firefox does better out-of-the-box is in HTML5 Canvas, as measured through testing by CanvasMark.
For the demanding JetStream 2 benchmark one of the most demanding tests for browsers at the moment, the Chrome on Linux it was 67% faster by Firefox on the same Intel Raptor Lake desktop computer.