Behind the times
Definition 1 of 1
Pro Tip 1/3Cultural Relevance
The phrase may imply a person or thing is not adapting to current cultural trends or societal changes. 
My uncle's fashion sense is behind the times, still stuck in the '80s.
Pro Tip 2/3Technological Context
Often used when technology is outdated, like old software or gadgets. 
Using a flip phone? That's quite behind the times.
Pro Tip 3/3Neutral Tone
The phrase isn't always an insult; it can be a neutral statement about being outdated. 
Their business model is a bit behind the times, but it works for them.