If the action or activity is still in effect, the present perfect continuous is used, as we know. The present perfect continuous is also used when the speaker wants to call attention to the long duration of the action, even if the action or activity is no longer in progress.
Many verbs can be used for this purpose. It's very hard to find Google examples of the present perfect continuous in which it's clear that the activity is no longer in effect, but here are a few:
"” Yet, despite all this, public and private policy makers seem obsessed with putting up new buildings, often at the expense of those that have been standing for many years.
"” Today he finally opened up to me and told me what he's been hiding all this time.
"” She just couldn't bring herself to say something along the lines of, "The game's up! What I've been saying all these years is no good any more".
"” Once, she had prided herself on speaking bluntly, honestly to her daughter. Only recently has she admitted that she's been lying all along.
In a past context we can see the same principle of emphasizing duration with the past continuous instead of the simple past:
"” Her presentation [about the new law] was merely the icing on the cake. Johnny had been diligently pushing for this legislation for about a year and his efforts clearly paid off.