I use emojis very sparingly, usually at the end of a sentence analogous to a punctuation mark. I never use more than two in a row, and never more than one of the same one.
In texting and messaging apps (as well as emails if I'm using Outlook) I may respond with a single emoji, often ๐, to indicate that I received the message and will comply with any requests.
The above demonstrates what I believe are the ideal use of emojis, as a compact way to express an otherwise unwieldy response, or a way to convey things like tone of voice and facial expression that is present in a face to face conversation but not in writing.
However, In my opinion, emojis rob the conversation of any gravitas whatsoever, so responding to "My dog died yesterday" with "I'm so sorry ๐ญ๐ญ๐ญ" makes it sound like you're making light of the situation. I get others may not feel the same way, so I don't call them out when they do it, but it rubs me the wrong way personally.
Most screen readers will read out the unicode description of the character or render the description as a transcriber's note on a braille display, so ๐คฎ is announced as face vomiting and written โ โ จโ ฃโ โ โ โ โ โ งโ โ โ โ โ ฌโ โ จโ . If you spam a bunch (๐ฅ๐ฅ๐ฅ๐คฃ๐คฃ๐คฃ) it can quickly get very long.
It's also apparent that people use the "wrong" emoji for the situation, and I don't mean in the sense that the semantics of the symbol have widened or changed with usage. ๐ is often used to express sadness, when the description is "face with tears of joy". ๐ข"crying face" would be much more apt.
