AFP vs SMB on HSierra and Mojave

Hi all.

From two or three version of macOS (I'm not sure on it) SMB is the default network protocol on Mac. Of course, Mac users can also use AFP by activating it in System Preferecens>Sharing>File Sharing>Option and, when connecting to a server, typing "afp" manually.

From mt tests, AFP is actually the fastest and stable protocol between Mac and Mac and between Mac and NAS (that use Ext4 filesystem): I say that because AFP seems to be fastest to public a shared volume, fastest to show metadata (like icons of the files) and easier to using from Application like Word, InDesign, Photoshop etc... when I use "Save as" or "Save" directly on server and not in local.
But this is my impression: I don't know why Apple is slowly switching from AFP to SMB and which features has SMB compared to AFP.

More, I like to hear some other consideration from Mac user on it.

Tnx in advance