The PlayStation 5 just received a big firmware update today, adding in a batch of new features and improvements to the experience. After installing the update, you'll be prompted about updating your DualSense controller as well.
There's no information on what the software updates for DualSense controllers do exactly, but as always, it's best to make sure everything is as up-to-date as possible to ensure the best functionality. So, when your PS5 tells you there's an update for your controller, plug it in via USB and get it done — it only takes a minute. You can also tell the PS5 to notify you again in 24 hours if you really can't be bothered straight away.
Just a little FYI, really. After updating your PS5, get those DualSense pads updated too.