dont agree with that, the navy was an absolute power unit which is why Denmark got involved in the Napoleonic war to begin with (well if we exclude the minor skirmishes that happened with France in the beginning)
placement in the center of 1 of europes most important tradelanes also made the country extremely important for the trade and incredibly wealthy.
and then there is the 30 years war, while Denmark certainly didn’t do a great job this is more about a series of bad decisions and broken promises from their allies than anything to do with capability, the country was asked to go in since it was seen as the most capable country that was in a position to actually interween at that point, had that war gone different or had Denmark simply not gone in (at least alone) then europes borders today would look different.
but anyhow, was Denmark as important as Britain, France and Spain? obviously no, was it so unimportant that no one cared about it? the answer to that is also no, Russia in particular wanted to be on good terms since their weakness in naval was basically nullified if the country helped them out, Britain always held a good deal of respect to the Danish navy and it is worth pointing out that when the 2 sides finally did engage it ended tactically inconclusive and tied a big chunk of the royal navy up for the rest of the war.