Apologies I'd prematurely said this was fixed but I was mistaken
https://roadmap.ploi.io/projects/7-bugs/items/1177-cant-install-ploicli
I still can't install via composer global require ploi/cli or composer global require ploi/cli -W

Can you try running composer global update?
This updates all the dependencies you've installed globally.
After that, try again installing the CLI using composer global require ploi/cli
Please let me know if this helped!
Aah that's got it kinda! So doing global update did update packages but still didn't fix the issue
After running composer global why symfony/console I saw a bunch of old global packages so I just uninstalled them and then ploi/cli finally installed!
Alright, good to know! Very unfortunate, but glad it worked out.
If you need help, or find any bugs/weird things, feel free to reach out!
Have fun using the CLI :)