Earlier quoted context omitted.
They didn't "remove vowels" as much as started out without them! We're talking times when writing itself was utter novelty, a curiosity performed by a handful of scribes primarily for accounting purposes, and of no great importance to daily life at all. By contrast, cuneiform (of Sumer origin -- a traditional rival power to ancient Egypt) did have vowels. A surprising amount of history—writing, speaking, war, splitti…
> By contrast, cuneiform (of Sumer origin -- a traditional rival power to ancient Egypt) did have vowels. One caveat: As I understand things, Sumerian started out without vowels (or consonants), much like Chinese, but developed phonetic usage over time (unlike Chinese :( ). This has resulted in early texts being much harder to read than later texts.
Unfortunately, those characters are mostly pretty old and the pronunciations have diverged. So the situation is a bit similar to that of English, where the orthography is a good guide to Middle English pronunciation, but confusing for modern people. Linguists love that it enables them to reconstruct ancient pronunciations, of course.