"Have been + verb-ing" vs. "have + past participle"

In "I've been waiting for you for seven years" the focus is on the act of waiting. Maybe you want to emphasise how long seven years is, or make the listener understand how patient you have been.

In "I've waited for you for seven years" the focus is on the result of the wait. Now, perhaps you want to emphasis that the wait is over, or you are unwilling to wait any longer, or you are really angry now.

This gives a quick overview.

I am unaware of any difference between “I’ve been waiting for you” and “I have waited for you”. I would use these two completely interchangeably.

It's not "Have Been + Past Participle," which is the Present Perfect Passive.

It's actually "Have Been V+ing" also known as the Present Perfect Progressive or Present Perfect Continuous.

It is used for an activity that started in the past and still continues to the present.

On the other hand, the Present Perfect Simple (Have P.P.) is used for completed actions.

Simple examples would be:

Ex. Oh, are you ever gonna come back? I've been waiting for you for seven years!

while

Ex. I'm sorry. You're too late. I've waited for you for seven years and now I'm a married woman.