grammar - For the last Х years - with which tense

As far as I know "For the last Х years" requires the Present Perfect (continuous) and means that the action is still taking place.

I have been building a house for the last three years.

However, I have come across a puzzling example in an American magazine.

"..... Today is my first day driving a cab. I've been driving a hearse for the last 25 years."

I understand it as he doesn't drive a hearse any more. Why the Present Perfect then? Driving a cab is in the past now. Wouldn't it be better to say :"I was driving a hearse for the last 25 years"? or "I was driving a hearse for 25 years"? Or is it OK to use the PPC in such contexts.

Another example, "For the last 30 years our Institute offered a summer math program..." (found in the same American magazine) I understand it as the Institute doesn't offer the summer program any more. Am I right? We can see that the writer uses the Past Simple here. I thought it would be very fitting to do it in the first example as well.

So, I'd like to know: Is it OK to use either the Present Perfect (Continuous) or Past Simple (Past Continuous) with "for the last Х years"? But it seems like it:

"I have been driving a cab for the last 25 years." may mean two different things

1) I am still doing it. 2) I am not doing it any more. Is it possible?

Let's take the last example:

You were waiting for a person for 30 minutes but the person didn't show up and you went off. What would you say to the person on the phone 2 minutes later after you went away from the waiting spot?

1) Hello John, you know I have been waiting for you for the last 30 minutes. But - alas!

2) Hello John, you know I was waiting for you for the last 30 minutes. But - alas!

3) Hello John, you know I was waiting for you for 30 minutes. But - alas!