What's the function of Non-addressed Decisions, when Directives already existed?

Question

1. I read the emboldened sentence, but I still don't get what Non-addressed Decisions' past function is?

2. What's their function now?

3. Aren't Directives "an instrument that was directly applicable but lacked direct effect"?

Directives now have Vertical Direct Effect. The No Horizontal Direct Effects rule has exceptions like the Wide Definition of States, Incidental Horizontal, Indirect Effects through National and Primary EU Law, Indirect Effects through Medium of European Law.

Note I'm asking about JUST type 2. Robert Schütze. European Union Law 2 ed. 2018. pp 92-93.

This development is now recognised in Article 288(4) TFEU that allows for two types of decisions: [1] decisions specifically applicable to those to whom it is addressed, and [2] decisions that are generally applicable because they are not addressed to anybody specifically.

p. 94

bb. Non-addressed Decisions

While not expressly envisaged by the original Treaties, non-addressed decisions (decisions sui generis) had become a widespread constitutional phenomenon within the European Union.⁸⁹ The Lisbon Treaty has now ‘officialised’ them in Article 288 TFEU. But what is the function of these decisions? In the past,

p. 95

the Union had recourse to these decisions – instead of regulations – to have an instrument that was directly applicable but lacked direct effect.

Answer 1

Directive

A directive is an instruction that each member state must follow when making their own laws. In other words, directives govern national legislation.

Decision

Decisions are used to clarify regulations and directives. Often decisions only apply to one or some member states.

How the European Union works

I think in the past, a non-addressed EU decision was taken more as advice that should be followed to some extent, but not necessarily in its entirety. That's why Article 288 now explicitly says:

"A decision shall be binding in its entirety."

Article 288