If I recall correctly, it wasn’t about appending an emoji to the end of your comment like you just did, but rather about the type of comments that would be 50% or more emojis, that for some reason are very prolific on the Internet.
And I would say there were two good reasons for this. First, these comments rarely conveyed much meaning, the emojis were used to exaggerate the emotional message, but little else.
The second (and more serious one) was the decline in English proficiency among native speakers (especially youth) that was ascribed to use of emojis and emoticons.
Google commissioned a study back in 2018 that showed, that most adults are not confident in their own spelling, and blame the emojis for it.