How we cleanup system memory on our macbooks

lots of device support

every time you plug in a device type to xcode you get a duplicate

cd ~/Library/Developer
sudo du -sch .[!.]* * |sort -h

/Library/Developer/Xcode/iOS DeviceSupport was MASSIVE rm -rf the applicable files

lots of simulator device

per this

cd ~Library/Developer/CoreSimulator/Devices
xcrun simctl delete unavailable

if that doesn't work: this and this

Look at Docker Containers

per this