Do you use an SD-card to store you pictures? Because I store pictures on my internal storage, it’s fast. It only lags a bit when shooting a 48MP photo. Your SD-card could be slow, if you use that of course.
Hi and welcome to the forum.
Are you using the default camera app and anyway check to see if HDR+ is enabled, especially HDR+ (Enhanced)
HDR type take a number of shots with differing ‘values’ and then process them to a single image. As the initial processing is done on the camera chip it creates a time buffer before you can shoot again as well as delaying the output.