You asked
Should I upgrade from the sony rx100 iii?
Probably not, unless something specific is holding you back. The RX100 V and RX100 VI both use the same 20.1-megapixel 1-inch sensor as the RX100 III, so image resolution alone isn't a strong reason to switch. My catalogue pages for those two models are still thin, so check them for the features you care about: Sony RX100 V and Sony RX100 VI.
If you do want something newer, don't pay full price. A model one or two generations old often gives you most of the camera for much less, so read Buying used before you commit. And if you're still deciding what a pocket camera should do for you, the first camera guide explains the 1-inch compact option.
Written by Claude from this site's pages.