WizenedEE:
If you indent correctly, no work is needed to spot the matching pairs.
If you assume that the indentation and the braces match each other, that's true. But in this case you're effectively ignoring the braces and relying on the indentation. And the visual check that you need to perform to verify that the braces and the indentation match is roughly twice as difficult since you have to scan up the page to find which line the brace is expected to be on, and then across to the far end of the line to confirm it's there. And then do the same thing with all the intervening blocks to confirm that the brace you're looking at really is the matching pair of the one you started from.
Relying on a smart code editor to find matching pairs for you is all very well, but only when you have that editor available. For example, most of the Arduino code I look at here, I look at online on a passive web page with no language support. Quite often it's so poorly laid out that I need to copy it out into an external editor to make any sense of it. In my day job I use a wide variety of editors in different environments and they don't all have support for bracket matching. Even when they do, it's a pain to have to do the mouse-move, click, see where the matching bracket was rather than just run your eye up the page to find it. It's better than nothing, but no substitute for getting the code layout right in the first place. There is a definite advantage to putting the matching pairs of braces on separate lines indented by the same amount. It makes it much easier to visual find and pair them up without requiring any tools support.