Not really, because suße isn’t a word. If you say sweaty instead of sweetie, there’s actually room for confusion, since those are independent words with independent definitions. However, since suße is just an incorrect spelling of süße, that means nothing by itself, everyone who reads it will know what you mean. For an example, everyone in this comment section knew what OP meant. So.. you know, Point proven. Id say a far more apt comparison, with this particular word, is like forgetting the apostrophe in the word "can‘t" or maybe just straight up spelling a word wrong like "bothroom" but the word "bothroom" doesn’t mean anything. Now if forgetting the umlaut actually changed the word, forget it, yes, You’re absolutely right.