I guess I'll end up representing the extreme end of the scale here but after many years of global travel both for work and recreation I've gradually gone from carry-on only most of the time to ultra-minimalist and have never been happier. DW has joined me of late, though with a bit of carping.
Wheeled luggage is not just useless but hazardous in both the third world and on packed public transit (metro station escalators, trains) so we avoid it like the plague. Instead we use top-quality travel backpacks, which are super-comfortable as long as you keep them light. To do so that means they have to be light to start with: around 2 pounds - not the 4-5 pound expensive, complex bags made for so-called digital nomads.
I'll include a link to the single best source of info on these bags and this kind of travel I've found below.
A further distinction is between bags that are maximum legal carry-on size on most airlines (standards do vary and are stricter outside the U.S.) in the 30-35 liter range and personal-size bags that fit under the airplane seat. We most often travel with one of these: Cabin Zero ADV Pro or ULA Dragonfly. Inside that pack we have a super-light packable daypack from Osprey or Sea To Summit or a 6 liter sling bag and that is what we put our plane stuff (earbuds, water bottle, snacks, charger) in once on the plane and is also our sight-seeing bag on arrival at our destination. When packed into its own pocket such a pack is the size of an energy bar and weighs a couple of ounces
Four pairs total of Ex-Officio underwear, 2 pairs of pants (or 1 and a pair of shorts for trips to SE Asia), a pair of comfortable but neutral color shoes with tread suitable for both streets and trails on our feet (plus super lightweight Xero shoes sandals), 3-5 capilene or merino wool shirts (short and long-sleeved as needed), a smartphone with backup charging brick, USB-C charger with adapter if needed and a super-lightweight puffy coat or Patagonia Dragonfly rain coat. For longer trips we may take an iPad mini or Kindle. Total pack weight is usually in the 11-14 pound range.
This kind of packing takes some getting used to, and an investment in key lightweight clothing that can be hand washed and will dry overnight but once that's done it's incredibly liberating to never worry about overhead bin space let alone lost luggage.
Here's a video on carry-on size vs personal item packs:
https://youtu.be/SVlBJyW1FSw
And here's the same guy sharing what he took on a recent 2.5 week trip to Ecuador and the Galapagos Islands:
https://youtu.be/mCLK16qUtNY
There's a pretty large worldwide community of folks who travel this way - including plenty of people in their 60's and 70's.