Then you probably have to buy a case, screen protector, headphones, etc.
A data plan may perhaps equal the monthly amount of gas a car needs. But then you have insurance, maintenance, and parking. Overall, we are talking an order of magnitude of difference.
Unless you really need a car, like some of the commenters do, a car is truly a money sink. Car manufacturers seem to keep missing this point, which I honestly find surprising.
Why spend money on a car when I can spend it on a laptop, smartphone, music, movies, apps, case, screen protector, headphones... and I spend money on a whole bunch of other hobby-related things besides those.
Really, what kind of money sinks did my parents have when they were in their 20s and 30s in the '60s and '70s? Video games weren't a thing, home video wasn't a thing, personal computers weren't a thing, cell phones weren't a thing (some of these existed in the late '70s, but they were extreme niche products the general public didn't know or care about). About the only consumer electronics that were around were TV, radio, records, and consumer audio/visual technology didn't constantly evolve like it does now: if you had a color TV and a stereo system (record player, radio, speakers), you never had to upgrade, and they were built like rocks and lasted forever. The only media you could buy were records and books.
So that's it: you'd buy one TV and stereo system your whole life, you'd have a record collection and a bookshelf, and you had a pile of money left over. Why not put that into a car? See also: mortgages and expensive classy furniture, neither of which are particularly popular among Millennials either.
In a large city just parking alone can be a MacBook every couple of months unless your employer subsidizes it.
Cars that cost less than macbooks also are going to need (relatively) expensive repairs or even replacements on a similar if not more frequent basis than the macbooks gets replaced.
And for the record, I don't know any millennials buying the high-end Macbooks, either. I've always bought the Air for myself, and even though my jobs typically buy me a Macbook Pro, it's not the $5K ones with all the bells and whistles, it's a $2000-ish one with a few minor upgrades from minimum.
A car, on the other hand, costs more. I figure upfront costs for a cheapish used car being around $3,000 - $5,000. This costs more than a couple of laptops and smartphones combined - and it is all at once. At least the phones might be subsidized by the phone company (though I read that is changing there).
In addition, there are all these fees associated with cars. You have taxes and plates and insurance (which can cost as much as internet every month). These cost more with newer cars. Newer cars you have car payments, followed by some time with overlapping maintenance fees and car payments. Used cars with a loan have that as well: Without a loan, you still have maintenance costs and fuel costs to consider.
Seriously an unfair comparison.
Besides, even with a vehicle, the expectation is really that folks have a cell phone and internet service: Computer instead of television of days gone by. Heck, you need this sort of thing for job and apartment shopping. Sure, theoretically there are libraries, but not everyone actually has access to them. (there are places in Indiana without a local library, and any they can use charge to use them, for example).