I've been trying to install elementary on my mid 2010 17" mbp. I've created a few different flash drives using both Etcher and DD. I've even verified the ISO hash. No matter what media I use I wind up here after selecting the bootable usb. Google has not been helpful in figuring this out. Anyone else seen this?
I recall trying to install Linux on a 2007 Macbook and several distros not working. I guess try a different distro. I don't know why some work and some don't but I'm just gonna blame Apple. Try Fedora or endeavourOS. I even found this script to install Elementary's Pantheon DE on Arch Linux.
Edit: Also Debian might be worth a try.