Well.. you seems to be very optimistic about Lankan cricket. I am not so much sure about it. A win or two once in a while is not going to do them any good. What they need to do is to win matches regularly, especially during major ICC tournaments. On top of all this, Sri Lanka is currently undergoing an economic turmoil, and that will have an impact on the quality of cricket. In the long run, I am not very hopeful about the situation in Sri Lanka, unlike the case with either India or Pakistan.
No doubt the Sri Lankan team has a great and well-established history in cricket. They have played many matches and achieved numerous wins, but they are not performing consistently like others do. The reason for this, as you already mentioned, is their economic condition. Under these circumstances, I don't think they will perform well. Considering their situation, I believe they are still performing admirably despite all their crises. If there were another team in their place, they might have left cricket very early, but it is the Sri Lankan team that continues to play.
They are facing a lot of issues, such as their economic situation, which will directly affect their performance. If they acknowledge these issues and fulfill their needs, along with making better investments in the team, they will perform exceptionally well once their problems and deficiencies are addressed.