How to set such an ACL?

Question

linux

ordered setfacl -dRm u:www:rwx,g:www:rwx /folder, finally received

# file: folder
# owner: root
# group: root
user::rwx
group::r-x
other::r-x
default:user::rwx
default:user:www:rwx
default:group::r-x
default:group:www:rwx
default:mask::rwx
default:other::r-x

And what, it is obligatory to specify a default for all users, it is impossible to shift this to standard rights, but to make separate ones for a certain user?
I set the default so that these rules are inherited for all files and folders created inside.

Also, the mask appears, as I understand it, as a result of rwx for everyone.

---
In general, what I want looks something like this

chown -R www:www folder
chmod -R 0770 folder

Only now it is necessary for all files and folders created inside and inside these folders to apply this

-
If inside such a folder

# file: folder
# owner: root
# group: root
user::rwx
group::r-x
other::r-x
default:user::---
default:user:www:rwx
default:group::---
default:group:www:rwx
default:mask::rwx
default:other::---

create a file touch folder/file
, then the file looks like this

# file: folder/file
# owner: root
# group: root
user::---
user:www:rwx                    #effective:rw-
group::---
group:www:rwx                   #effective:rw-
mask::rw-
other::---

what kind of mask is this and why is it like this?