I hear that. My hiking partner is often far heavier than I am. For two or three nights, my typical pack weight is 16-17 pounds. His pack weight is typically 33-35 pounds...twice my weight.
This is not always by his choice, though. I am retired, my children are out of the house and everything is paid for. My partner works, he is paying for his house, he has other things that prioritize his expenditures. While his children are out of the house, he is in the process of remodeling it. His wife no longer works. And, he has a number of other interests. He hikes and camps out only about 3 weeks per year.
He has an old military style sleeping bag that weighs about 4 pounds. He simply does not see the wisdom of investing $400 or more in a good down bag. This is about a 2.5 pound difference between my bag. He uses an older Therm-a-rest Guidelite, about two pounds of pad. I use a 13oz Neoair...over a pound difference. He got an excellent deal on an older JetBoil, about 1 pound plus 7oz for fuel. I use a 10oz cook kit for 2 nights...more than half a pound. His pack weighs about 4.5 pounds and is quite large (mostly for the sleeping bag.) My pack weighs about 15oz, with the pack frame/pad, a 3.5 pound difference. He has a 14oz water filter. I use a 4.5oz steripen. And so on...
He has some older gear that works well. I like the way the jetboil cooks, but dislike the weight. He knows a LOT about the woods and camping, he has been out since he was a teen...better than 40 years. I have managed to get his weight down 10 pounds over the past few years. I gave him a long handled Ti spoon and explained about using it. As a screw driver and a an eating utensel. He dropped the stainless steel "camp" kit he carried, knife, fork and spoon, AND, the larger swiss knife he carried. He dropped the cup he carried. He dropped the old Eureka tent, we share my tarp. And so on... He tried trail runners, and went back to boots. I did the same after three tries with runners. (They do not work well in the ADK's.)
Anyway he started out doing the High Peaks with me about 7 -8 years ago carrying 47 pounds. By carefull planning (reducing his food to a minimum) dropping unneeded stuff, and sharing shelter with me, he now carries about 33 pounds without any dollar outlay.
But he doesn't buy a lot to replace his heavier gear. He likes the Steripen for instance. But he avoids buying one because he has other places for his cash. Same for his own tarp. He doesn't have the time to make a stove, wind screen and pot set-up. Nor the time to dink with smaller items. I carry the bear ball, so he drops his bear line and rok-sack. He has added a few yards of duct tape to his kit, and dropped his first aid kit (except a 1/4oz vial of alcohol.) Last trip his pack (4500ci) was not full anymore. He mentioned that he needed a smaller one.
Anyway, much of what you do when going out with a good friend is not mention the size or weight of gear. If HE brings it up, then you can tell him what you do and why. I don't think telling him he is wrong is very productive, though. Old timers that have hiked together for a while often wouldn't change, anyway. Sometimes, they will recognize they are getting a bit older and the need to get lighter. They may seek your advice if you do not press them.