I managed to handle a two weeks trip across the US with a carry on.
7 shirts/socks/boxers additional sweater and trousers, toothbrush and razor, half of the pack was used for my camera and the lens.
overnight cleaning service and basic amenities in the hotels made uo for the rest.

same for the 10 days at fiji, where the only problem was the beach towel or whatever its name is.

I travel lighter, happier, and cannot remember the last time I checked a bag.