Should I read demon slayer or wait for anime Reddit

Depends. A lot of people are watching Kimetsu No Yaiba for the animation alone. That, or the cuteness behemoth that is Nezuko. If you're interested on it because of those two reasons, then don't read the manga and stick to anime only.

It's nowhere near as visually stunning as the anime. You won't get the stellar fight scenes or the Nezuko Cuteness Overload moments. Case in point: the author can't draw hands or feet consistently.

However, if what interests you is the plot or the characters, by all means, read the manga. I personally started watching KNY for the animation, but went ahead and read the manga for the character arcs. People hate on Zenitsu and Inosuke a lot in the anime-only circles as "they scream a lot", but they're my favorites. Zenitsu has a very satisfying character arc, and Inosuke gets some surprisingly emotional moments.

So... It's up to you and why you're watching Kimetsu No Yaiba.

Edit: Sometimes the sloppy drawings elevate the manga, though. There's some frames that are poorly-drawn (seemingly) on purpose for comedic effect, and they're pure gold.