I know, some posters have turned this into another "kids these days" thread as seems to happen often, but it's also based a lot on their own very limited world and I'll go out on a limb and say a LOT of pre-conceived and unshakable biases.
For the record, I am 35, and I mow and do the vast majority of our car repairs. I gave up oil changes on my wife's new(ish) Atlas because I found out she has it for free for the first 30K(after I'd already done the first one myself...). BTW, I also have a bit of a hobby now of repairing/restoring old lawn mowers(Lawn Boys specifically). I don't wash cars at home mostly because, for reasons unclear to me, our house doesn't have an outside spigot, but I can honestly do better going to the car wash stalls up the street(I take my own soap and other cleaning supplies, but like their pressure washers). I do generally wax at home. Hooking up a water hose for the times I really need it, like cleaning the gutters, is a "fun" affair of unhooking the washing machine and depending on where I need it sometimes disconnecting the dryer vent to run it out there.
Looking around us at our neighbors-
On one side we have a mid-50s single lady who was always active outside up until about two years ago, but a back injury and surgery killed most of that for her(I mowed for a year for her, but had to bow out-between a 1-year old and my wife and I both working full time, finding the time to do ours is hard enough).
Neighbor on the other side is a 50s couple who are always out mowing and washing their cars.
On down is a couple probably a few years older than my wife and I. He has a few Camaros of different ages and some other old vehicles that he's always tinkering with. A street behind us, there's a young guy(I'd guess late teens or early 20s) who always has another interesting pile of rust that he's drug home and is tinkering with. I've seen him with a few different 70s pickups and some other odds and ends-I doubt anything much newer than 1980. There's no mistaking him, either, as he considers mufflers optional and anything more than a glasspack too restrictive.
I have a lot of hobbies, and am a collector at whatever I do. One of the things that's really surprised me is the number of fairly young people who I will connect with over hobbies and who know a LOT. I've collected American pocket watches for about 15 years now, and unfortunately the quality of information I've seen shared on Facebook has dropped as compared to message boards and the like, although a lot of the really bad/wrong information I see comes from the old guys who never bothered to buy anything more detailed than the big price guide(which is overall a terrible reference) and think that makes them an expert. A few months ago, I bought a sort of rare 1960s Nikon lens from a guy on Ebay and ended up talking to him a lot and doing a lot more trading. He's in his 20s, is SUPER into early Nikon Fs, and has sold me some great pieces from 1959/1960(the first year of the Nikon F). The interest is out there, and honestly I find that for people who are serious about their chose collecting, the internet has on the whole improved the level of research and scholarship in those areas.