I dont think its that unreasonable. A flat tire happens so rarely, and for most people, they can just call a tow truck. For most, I dont think its worth carting a tire and wheel around for potentially zero use over the life of the car.
Some people definitely need spares, but realistically, most dont.
My minivan has a donut spare that is stored under the car (inside a cover). Super easy to get to, and never in the way. The tire and winch mechanism together adds maybe 30lbs of extra weight.
I'd rather have it and not need it than need it and not have it. I couldn't imagine the embarrassment of having to call a fucking tow truck because of a flat tire.
The number of people who would even know how to change a tyre is unfortunately decreasing. Manufacturers therefore have less reason to include something that requires allocating space, carrying extra weight, and a small extra cost for each car, because they know not enough people are going to care about the loss of a spare to make a difference to sales. I'd wager this is particularly true for EVs as they seem to attract a lot of people who are scared of basic maintenance. It's pretty poor of a company to not include a spare on something that's advertised for use on dirt though, even if the model in question doesn't actually seem like something that its buyers will actually take off the tar.
I personally would want a proper full sized spare in any of my vehicles, though I'm prepared to make an exception for my motorbikes due to the obvious logistical problems. Space savers are better than nothing but then you have to deal with speed restrictions and having to change wheels twice if you get a flat on the front. It's rare for me to get a puncture but it's nice to know that I can just quickly change wheels and carry on even if I somehow managed to put a big gash in a tyre or bend a rim. Even for just a basic puncture in town I can't imagine wanting to faff around on the side of a road for ages waiting for roadside assistance to come and fix something I could have done myself and been back on the road in 15 minutes.
Our EV doesn't have a spare, which I wasn't concerned about as I've had maybe two flats in my driving history and one of those I just pumped up and drove to the tyre shop for a repair.
What did catch me out recently was not having a jack. It makes sense though - car has no spare, so why include a jack?
We got a screw in the tyre a few weeks back and it was leaking too bad to pump up for even a short drive. I figured I'd jack up the car, take off the rim, and take it in the wife's car to the tyre joint.
Things to note:
No jack, as mentioned. Went to the local auto store and bought a pretty mid range scissor jack that looked like every other car jack I've ever used.
EVs are really bloody heavy. A standard 1600KG scissor jack could barely move the thing. Went back and bought a much heavier duty trolley jack.
A 3200KG trolley jack makes lifting the car easy, but the jack itself is huge and leaves no space on the lifting points to put jack stands.
An EV is really stiff - lifting the rear passenger side resulted in every wheel except the front drivers side coming off the ground.
Didn't want to leave it perched on a jack and a single wheel, so took the tyre off and ended up replacing the screw in the hole that was leaking with a bigger screw... Then pumping it up and driving it to the tyre joint.
Moral of the story - might be easier to just carry a small selection of different sized screws and a screw driver.