The immigration officer here in Dubai inconsiderately left a whole empty page between my last stamp and the UAE stamp.
Does this waste the page or will other immigration officers still stamp in between?
They will stamp in between - as long as there is room for a stamp.
Personal experience in Dubai has meant they tend to put all your frequent stamps closely together too to avoid taking too much room.
Quite often a busy immigration officer will just find a page at random and put a stamp there.
Nothing inconsiderate about it, it's just how they work. The stamp may be on a page of its own, leave empty pages, or be on a page already containing other stamps.
In rare occasions I've even seen them place stamps over other, older stamps, not seeming to aim for any specific spot on the page at all.
Another immigration officer will just see the empty page and put his stamp there at some point. Or maybe on exit from Dubai they'll place it there.
A Passport is not considered a sequential log, and most countries will just stamp wherever they want, whatever page opens first. Don't spend any thought on sequence and usage of pages.