Second, I think you're framing it as {truck + self pickup} vs {no vehicle + delivered}, but I think the more likely comparison is {truck + self pickup} vs {sedan + delivered}. Nobody's going to get a truck as their only vehicle that they'll literally only use a few times a year. They'll be choosing between truck and sedan as their daily driver (or truck as second vehicle). In the replacement case in particular (truck vs sedan) the friction delta is very small.
If you own the vehicle and it breaks you have to fix it - but most of the time it isn't broken. You need to pay insurance, but that comes in a regular bill, and so is easy to budget. In return for this you get a vehicle ready to use when you want to.
If you don't own the vehicle and need one there is a lot more friction: you need to figure out where to get a vehicle. More than once I've gone to get one and found they were sold out and so I couldn't rent when I needed one. More than once I've gone to get one and discovered the fine print didn't let me use it for what I wanted.
Open the app. Oh no, the car that's near my apartment isn't available when I need it. Ok what else is around? Ehhh the BMW is pretty expensive and unnecessary. Ah here's a Honda... but it's a 25 minute walk away.
Ok so I have to walk 25 minutes just to start the car. Then I can go where I want to - but if I bring anything back I'll have to find street parking in front of my apartment building to unload. Then I have to bring the car back to its spot, and then walk another 25 minutes back home.
Oh and don't forget to gas it up, because unlike owning a car, with a carshare more often than not you have to gas it up on the way back to avoid a penalty. You roll your eyes slightly at not just having to drop by the gas station but literally paying for the rental time to do it. But it's fine, whatever.
Like, I get that lots of people find this to be fine (I did, for over a decade!) - but it's anything but low-friction.
Traditional rentals are even worse - unlike carshares their pickup/dropoff locations are nowhere near you, so now you have to think about an Uber!
(US-centric view.)
If you live in a major urban center, sure. Paying hundreds of dollars a month for a parking spot would quickly convince me that car ownership was a bad idea. Otherwise, at least in the US, cities spread out to make room for the habits of their inhabitants. There's going to be easy parking where you live because that's what all of your neighbors want.
Of course, I agree that you should just have the deliveries... but I'm not seeing this as an argument why. The costs are not great enough.
Parking is similar. I can fit a small 2-door car into x% more parking spots in a city than a larger truck. So you can spend x% more of your time looking for parking spots. Maybe you're still looking for a spot when the car owner has already completed the errand.
As someone else mentioned, this friction is amortized over time so for some the psychological cost is lower, but for those who understand the principle of opportunity cost, it is a very real and tangible cost of ownership.
Now, if you’re in the 20% of truck buyers who really need them those are necessary costs but most people are buying them as a lifestyle accessory.
There’s also a fairly large group of people who live in urban settings who think they need all of that but are paying more than the cost of renting on the few times they actually do. Those people have been very good to the manufacturers’ profit margins but unfortunately all of the extra pollution and lowered safety affects their neighbors as well.
This is the real reason the SUV has eaten everything, because the so-called "crossover SUVs" and other small ones are just fancy hatchbacks, and a car with a square butt will always be more useful than a similar sized car with a trunk.