How to use a different entry point in the `roles` part

I have found this old thread that also suggests this: "import_role" vs "roles"

IMHO it would really be helpful, if there was some more information on possible deprecation plans.

Benefit… depends on the view. If you have a few simple roles, then

roles:
- role1
- role2
- role3

is quite concise. Doing the same in the new syntax is something like this:

tasks:
- ansible.builtin.import_role:
    name: role1
- ansible.builtin.import_role:
    name: role2

which feels quite verbose.

Yes, you could use include_role and loop:. But include_role has different semantics than import_role (which is closer to roles:).