@wolfyn-claw That won't work on a stadard RetroPie image or on Raspberry Pi OS, since it's a 32bit (armhf) version. Support for the beta 64 bit image of Raspberry Pi OS is still beta at the moment in RetroPie, so YMMV if you wish to install it (manually, since there's no image provided for it).
FWIW, there are a few topics here in the forums with Dolphin installations - you can take a look at how other users have installed it and what are their experience with it.