There’s an art to using anachronisms in storytelling. Just throwing it into a story because you’re too lazy to make the period adjustments rarely works. It can make a story feel poorly researched or poorly put together. However, it has its uses when used well.
Heavy use of anachronism by bringing things both backward and forward in time can be a great way to inject surrealism into a story. The TV show Archer (2009-Present) deliberately does this and even draws attention to it in one scene. A character rhetorically asks “What year do you think it is?” and the response is just “That’s a good question.” The whole show is littered with things that would place the show in different decades making it impossible to get a firm fix on the setting.
Another way to use anachronism is to draw a cultural parallel. For example, in the movie A Knight’s Tale (2001), modern music is used diegetically. Medieval people didn’t actually chant “We Will Rock You” at jousting tournaments but, it draws a comparison to how people do that at modern sporting events and shows how the jousting tournaments filled a similar cultural niche.
Of course, there are also settings where time travel is a part of canon events and in those fandoms (or in any story that introduces time travel as a plot point) anachronisms can be used to foreshadow time travel being involved before it becomes obvious. There’s a scene in an episode of Doctor Who (1963-1989, 2005-Present) where someone starts talking about how they need to look for subtle anachronisms to find the Doctor, only for him to roll into the Medieval castle on a tank while playing an electric guitar (a very unsubtle anachronism).
Like many tropes, if you want to use it deliberately, do it. Just make sure it’s deliberate and have in mind what you are trying to accomplish when you are doing it. If you do it correctly, it can have a wonderful effect on your story.