Only a limited subset of $\LaTeX$ is supported on this site, though enough for the vast majority of equations we'd be likely to use. Unicode symbols can still be useful, perhaps especially the more "pictorial" ones. For example, I recently edited a question and in doing so replaced many images by Unicode symbols, e.g. filled and empty circles, and numbers on circular backgrounds.
This certainly made the question easier to edit and annotate, and I hope easier to read. But are there pitfalls I should be aware of if using Unicode in questions and answers? For example, will what I did just be garbled by a screen reader, in which case for accessibility purposes I might have been better to use an image and provide an alt-text? Is Unicode well-supported these days, so if it looks good on my browser I can generally assume it will render okay for other people? Are there particular areas of Unicode we should avoid using?