Google are usually ones to get things right, like Google Maps and Streetview. Nobody 'wanted' this before it existed, but by now, everybody is used to it and it is bloody handy.
Originally, there were two modes for creating new posts. In 'HTML' mode you entered plain text and inserted your own html tags for formatting; in the other, you could highlight and format text in much the same way as you use Word. I preferred HTML mode because Compose generated a load of superfluous 'div' tags which buggered up the line spacing; you had to use HTML mode to get rid of them all again. But each to their own.
This time, in the face of zero demand from anybody, they've made HTML mode uneccessarily complicated. For no reason whatsoever, it now shows line numbers on the left, and you have to type in a line break tag at the end of each line and for every blank line.
Which is a pain in the arse:
Nothing else is as accessible as it used to be either. Detailed stats are now four or five clicks away which used to be two or three, and filtering your post list by labels is much more faff.