"C'mon, not another #@$*!!()** B vs N thing!"

The truth is that two unlike pieces could hardly be more equal (although it is also true that there are many positions showing a certain similarity between them, such as the following.)

https://lichess.org/editor/6Q1/8/1n4k1/1n4B1/6B1/1K6/8/1q6_w_-_-_0_1

In practice though the nod does tend to go to the bishop. Why? Well, of course everybody knows that the knight is a slowpoke compared to the other pieces (except the king). That one big strike against it though is thought to be compensated for by its strengths.

In closed positions, for example. Everybody knows how knights love 'em! There's just one problem with that: not all that many positions are closed. Indeed, the starting position is just about as wide open as you can get. And in general it takes a fair amount of cooperation (so to speak) from both players to close things up (in true knight-friendly fashion).

And that leads us right to the second point: everybody knows that nothing else likes closed positions! Which is the real problem. For a position favorable to knights generally clogs everything else up.

Knights also tend to rise in value whenever play (and pawns) are restricted to one side of the board. Yet positions like that tend not to offer up much in the way of winning chances (lacking such things as outside passed pawns).

Yes, it seems that whatever is good for the knight tends not to be good for anything else.

Still, the two pieces may not be quite so dissimilar as we imagine. Put your two knights on their usual squares in the opening (KB3 and QB3) and they hit all four center squares. Now take those knights away and replace them with bishops...and they still hit those four key squares. :)