While waiting for Mojca's attempts, for the moment I solved it by simply copying the folder of the old Mac in which I had installed the Standalone to the Mac M2. 
I have slightly modified the TeXShop scripts and everything works.

The log tells me:

This is LuaTeX, Version 1.13.0 (TeX Live 2021)

Compiling with LMTX, i read:

ConTeXt  ver:  2022.09.11 20:44 LMTX 

And compiling with MkIV (of the TeX Live 2022):

This is LuaTeX, Version 1.15.0 (TeX live 2022)

Tommaso

Il giorno dom 9 ott 2022 alle ore 09:23 Tommaso Gordini <illinguista1972@gmail.com> ha scritto:
Hello list,

I'm trying to install ConTeXt Standalone on my Mac (macOS 12.6 Monterey and Apple M2 chip) but at the end of the installation the ConTeXt-MkIV folder (where I install Standalone) on the disk weighs only 7MB (the tex tree is created, but its folders are empty).
I've never had a problem installing it on my old computer (Intel processor).

Do you know if it is a known problem?

These are the commands I used (taken from the wiki):

rsync -av rsync: //contextgarden.net/minimals/setup/first-setup.sh .
sh ./first-setup.sh --modules = all --fonts = all --goodies = all --context = latest --engine = luatex

Where am I wrong?

LMTX installation, on the other hand, should be successful (the folder weighs 297.8 MB, as much as the Standalone one should weigh).

Thanks in advance.
Tommaso