This should be a definitive answer, by looking at the grammar usage and its implied meaning:
Why we use present perfect continuous tense, when we can almost always use present perfect tense
He has been trying, which is a present perfect continuous, and
he has tried, which is the present perfect tense, do have a slight difference, and present perfect continuous is often used by native speakers to stress certain feelings.
present perfect continuous is used to stress the following:
Stress the fact that the action has repeatedly occurred several/many times, such as in this case.
Stress the fact that the action has been continuously happening non-stop, as in this case.
He has been studying for 3 hours
- Give a sense of complaining, such as
I've been studying for 3 hours! Let me go out!
present perfect continuous Cannot be used with stative verbs, those that do not use the continuous tense, such as
Ever since the accident I survived, I have believed there is a god.