One, is where was he going? He states at the start the plan is to go paragliding in the mountains. Apparently without his paragliding kit. And up into the mountains with nowhere to land. And they're really not the wheels for bush landings, so I don't assume the plan was to land wild.
He does have access to bush-appropriate craft though, he has an earlier video (this september) where he tells stories of how scary mountain flying can be, and the recurring craft in that video has the balloon-type tyres I expect from bush flying. ( https://www.youtube.com/watch?v=EMrwPPMTCmM )
But that earlier video raises the second question by repeatedly, consistently, shooting down his "I always fly with my chute on" statement.
I don't want to be "we did it reddit", but I can see why questions are being asked.
Even if you've got thousands of solo jumps, if you're doing a non-skydiving flight and feel the need to wear a parachute (very few pilots ever do this), you're just not going to wear a full skydiving rig. It's several times bulkier, it's harder to move in the cockpit, and it doesn't fit the purpose, which is to allow you to bail closer to the ground after running your engine failure checklist and not die.
The same with parachute. He probably felt that flying in mountains on 1942 piece of crap is risky so he needed backup and that flight suite was what he had available and can use at the moment. Better than nothing and good enough not to hustle to get something better.
Then the right answer is not take the trip in that airplane.
General aviation is pretty timeless, as far as vehicles go. If an airplane has regular annual inspections, decent maintenance as required, and a proven record of "not being a consistent pain in the ass," then it's likely to be quite reliable. I've flown stuff from the 60s and 70s, far older than I am, and I don't think twice about it. I do think about the general condition of the airplane and the maintenance trends I've seen, but age of the airframe just isn't a concern if it's still airworthy. If it were a "piece of crap," then it's not being maintained to something resembling airworthy. There are some out there, but they're rare.
And then, if you don't think it's the right plane for the trip, don't take that trip in that plane. Find a different route. Again, this is part of what you're supposed to learn in the process of getting your pilot's license. In general aviation, there are places you can't be, and there are places you shouldn't be - not in terms of "legal to be there," but in terms of "stupid to be there."
It varies from person to person, but a single engine, piston powered GA aircraft can't do an awful lot of things people would like to do with them. Or, at least, can't do it consistently. I personally think night single engine IFR is insane without a turbine up front and anti-icing equipment, though I've known people who do it. There are plenty of weather conditions you shouldn't fly in, and there are places you simply shouldn't be - downwind of a mountain ridge on a windy day is one of those places where the air will simply rip small airplanes out of the sky and dash them against the rocks. You can climb at 500 fpm up there? Cute, the descending air is doing 4000 fpm. On the flip side, if you're on the upwind side, you can get a nice boost from the rising air and, from what I hear, can damned near soar a Cessna on ridge lift in good conditions.
I'll tend to follow the valley, though, if I can find a route that goes where I'm going, and tend to skip as many ridge crossings as I can. It adds some time, yes, but I prefer to have an awful lot of big flat area under me in case the engine does go quiet.
If you're so concerned about flying in the mountains in a 1942 airplane, though, the right answer isn't to take a parachute and a studio worth of cameras. It's to re-evaluate the trip you're about to take and find a solution you're comfortable with.
The difference is that if you are already looking at a M1 Macbook Pro, the only downside from getting the top end one if you don't need it is cost. If that amount of money doesn't matter to you, then there's no significant downside.
Same with the Audi. If I'm looking at an A7 and don't care much about the overall cost, there's not really much of a downside to buying a S7 or RS7 as long as the roads in your area are decent.
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GP's example of a gaming PC was a good analogy for this situation because a gaming PC brings significant downsides for normal users over non-gaming PCs. They're bulky, can be noisy, definitely not portable, sometimes finicky, etc.
Even flight school planes aren't that bad, it's usually just the landing gear that is a little worse for wear :)
Like, if a high-end gaming PC is what you have on hand after upgrading, why not give Gramps a computer that will maybe take a little longer to bog down?
I can understand a skydiver-first, pilot-second being a bit dependent on their blanky kit.