I'm torn. TikTok is at least collecting and feeding tons of data directly to the Chicoms, including things like location data and images from government employee phones, including when they are in secure locations with said phones that have the app installed. At worst it's a Chicom psyop, dumbing down Americans (especially da youts) and spreading misinformation. However, banning apps is not easy, and it's very debatable if the feds have the Constitutional power to even try.
However, Fed employees, especially military, should absolutely be banned from having the app on any official device, and can probably be told to leave their personal devices with the app at home, away from any government building/worksite/ect.
Should Congress be focusing more on other things? Yes they should. Is this app an issue that needs to be looked at? Yes it is, again, particularly on government devices and in government facilities.