LOL - if you are a chronic overpacker, you'll think I'm nuts. We travel carryon-only. For my family of four for a trip of 4-8 days, we pack a total of four 21-22" carryon bags and two personal items (that fit under the seats). Fully packed, each carryon weighs about 20-22 lbs. and fits easily into the overhead bins of the plane.
EACH FAMILY MEMBER (DH, me, 11YO son and 9YO daughter) HAS - a single 21-22" carryon rolling bag, containing: (1) 2 pairs of sandals (1 hiking, 1 flip-flop); (2) 2 medium packing cubes holding 5 or 6 warm-weather outfits (shorts and top) with undergarments and socks, PJs, swimsuit and rashguard; (3) for me only, an ebags "Pack-it-Flat" toiletry kit with all of my non-liquid makeup items, the whole family's toiletry items and toothbrushes, razors, deodorant, combs, meds, etc.; and (4) for me and DH only, 3-1-1 bags with liquid makeup items, moisturizer, primer, our preferred shampoo, toothpaste, sunscreen, shaving foam and a laundry detergent pod or two (if our visit is going to be longer than 4-5 days, which means we'll schedule a mid-week pool morning and do laundry). Additional items (packed in small packing cubes and spread between the kids' luggage, which due to the smaller size of their clothes are only 75% full after all of their clothes are packed) include cereal, granola bars and Pop Tarts for breakfast, powdered coffee creamer, hand sanitizing wipes, glow sticks, autograph books/pens, a packable beach bag, swim goggles, disposable rain ponchos, clothespins and a cloth laundry bag.
On the way home, we've eaten all the breakfast foods we brought with us, so we have the equivalent of half a bag open for souvenirs. If we still need more room on the return trip, we just use the "beach bag," which one of the kids can adopt as their own "personal item" on the plane.
DH AND I EACH ALSO CARRY - a "personal item" for the plane (tote bag for me, backpack for him), containing our boarding passes, snacks for the flight, IDs, phones, electronics and chargers, earbuds, paperwork, everybody's sunglasses, MagicBands, a pair of shorts for ourselves and each of the kids to change into once we get to Florida. Tucked inside my tote bag is my "park bag," a tiny crossbody purse with all of the important in-park stuff - ID, credit cards, touring plan cards, cash, sunscreen stick, a couple of Band-Aids and some Tylenol, etc..
TO TRAVEL, WE WEAR - all of our bulkiest clothing: sneakers, jeans, T-shirt, ballcap (for DH and the kids) and hoodie. We're usually flying down when it's cold at home and hot in Florida, so we change into shorts on arrival and don't need the jeans again until we fly home. Our hoodies get only sporadic use (late at night, maybe, if the temperature drops too much), so there's no need for any of us to have more than one.
The key to packing light is to make a carefully-curated list ahead of time, and then stick to it ruthlessly. I used to always throw in a few extras at the last minute, "just in case." I learned over time that the "in case" never happens, and that if I'm not sure I'm going to need something, it should stay home. I also try to plan functional "capsule wardrobes" in complementary colors so that all of the clothing each of us brings can be mixed and matched easily.