What are arguments against the usage of a ticker / marquee on websites?

I was recently asked to add a ticker (with daily updates) to one of our HTML-based dashboards. (A ticker would be text scrolling through the screen. In the past you could achieve something like that with the marquee tag in HTML.)

I personally don't like tickers and think they are a thing of the last century, but that's not really a good argument. There have to be better arguments though, because none of the websites I frequently visit use tickers anymore.

Do you now better arguments against the usage of tickers?