Bad idea to do manually. Read more about what these are and why they exist :
https://en.wikipedia.org/wiki/Dynamic_linker
If you have problems with dyld files, you can rebuild them: get Big Sur version of Onyx and it will let you rebuild dyld libraries. But you will probably not save space, at least not much.
Those 128 and 250GB drives are really small for today...
I have Onyx (yes it is the version specified for Big Sur) on my iMac running Big Sur 11.6.1, but
I cannot see any option to delete or rebuild the dyld files. The Onyx version for High Sierraa does offer that option.
On my system that dyld folder takes up 9.91GB! The dyld_shared_cache_arm64e file is 222.36GB and the dyld_shared_cache_arm64e.map file is 756KB. How can these "arm" related files be necessary? This is an Intel CPU!
Considering the small size of the SSD at 121GB (split the default 1TB HDD and the 128GB SSD that made up the default Fusion drive), it would be great to delete that "arm" file at least, but Big Sur strictly prohibits that action.
Even with SIP disabled, using "sudo rm (dragging the arm file here)" does not work.
Any suggestions? (I am really not up to opening up the iMac to swap the SSD)