There are a lot of blind people on here, who use screen reader software to tell them what is on the screen. To help screen reader users, it's a good idea to use emoji rather than old-style smileys.
For example 😄 will be read out loud as "smile" because that's its alt text. However, :D will be read out loud as "colon D".
(Some old-style smileys do work with screen readers, but most don't. Emoji are safer.)
If you're interested in accessibiity, I strongly recommend following @weirdwriter
Good counsel, as we are used from you, @feditips 🌹!
🤔
But, to pick a nit: Is the reasoning correct?
A standard emoticon like the one in your example is a plain humble unicode character. There's no HTML tag with an alt attribute, characters simply do not have alt texts. Its images and other media that do. The "smile" is added by an English screen reading software.
It may be different when people use custom emojis provided by their server instance. My choice: I generally don't.
@weirdwriter
FediTips has moved!
Andreas, DJ3EI, he/him