A main problem for the Netherlands is, obviously, that it is a lot smaller than Britain (or even England), France or several other competitors. It can remain an important country. It will never to completely outclass England, France, Germany, Russia, China, the USA, etc. In the end, the base of the Netherlands is simply too small. Even if it were able to absorb all of Belgium, or parts of western Germany or Nothern France (like Dunkirk).
Could it maintain it relatively large colonial empire?* Mind you, the Netherlands did had a pretty good colonial Empire with Indonesia. Indonesia probably was the best colony any country could have, together with India. But, I would say that a POD in the late 18th century would be able to accomplish the Dutch keeping (former British) Guyana, the Cape Colony, Sri Lanka, Malaysia and the Dutch Gold Coast. Even a POD during the French revolutionary road could be able to accomplish it. If the Dutch East India gets its act together again, I would say that a significant Dutch Southern India is even possible. It is even possible for them in theory to gain some more colonies. I think a Dutch Western Australian settlement colony is possible, if you can get a reason for a Dutch settlement colony.
With an earlier POD even more is possible. There are several Carribean islands that could have been Dutch, like the Virgin Islands.A more competent WIC could mean that the Dutch could even keep some of Brasil and I think that in theory even a Dutch New York is possible, if you would realy want to.
In the end I would say that simply put the Dutch economy and politics (which were closely connected) became stagnant and corrupt. It needed something, maybe someone to make some major changes. Maybe of Johan Friso hadn't died, or Willem IV remained tadholder for longer, or even if Willem V would have been competent it might have changed a lot. In my opinion the key lies at the stadholders, because it were the regents who were corrupt and rich and relativwely satisfied with the current situation. They would never change anything. A stadholder might have.
Mind you, it might have helped if the Dutch cared a bit more of expansion into the Southern Netherlands and maybe expand their influence into NW Germany (like East-Frisia,Bentheim, Cleves). It would have given the Dutch a larger population base, something they needed. Especialy in the 19th century.
*Well, no. In the end nobody can. Obviously.