I'd love to see some links to recent (last 5 years or so) studies supporting this. I know this was popular 20 years ago, I just doubt it is true anymore. In Bill Gates's book how to avoid a climate crisis, he makes scores of suggestions. None of them is pack everyone into densely populated urban centers. The number #1 source of greenhouse gases is building things responsible for 31% compared to transportation which is only 16%. Single family homes, can and generally are built primarily of renewable wood, where as skyscraper have to be built with steel and concrete. Steel is very hard to make greener, and concrete is virtually impossible because it relies on chemical reaction which produces a ton of CO2. This means there is an order of magnitude more CO2 being released to build 1,500' foot condo than 1500 foot house.
Apartment buildings are also one of the biggest barriers to more widescale EV adoption. They require extensive retrofiting to install charging stations, and they lack sufficient roof space to put on solar panels to generate electricity. I'm essentially off the grid, my PV system produces as much electricity as I consume in my house, plus charging my EV. That's something an apartment dweller can't do.
Your argument assumes I'm only talking about high rises. As already mentioned, I'm not. There's a lot of middle ground between single family suburban sprawl and high rises.
In most places it's feasible to build up to 6 stories (about 85 ft) using wood construction. Blocks of mixed use 6 story buildings are far better than sprawl, and make for a pleasant neighborhood footprint. This is how most European cities are configured, with relatively few people living in central districts. And you know what, it makes for really nice, livable cities.
Single family suburban sprawl, on the other hand, IS much more carbon intensive, including construction itself. Consider how much cement and pavement is used to create a typical subdivision with relatively few homes. Sprawled out roads and sidewalks, drainage, and earthworks. Each home needs its own cement foundation (vs. multiple homes per foundation). Then every home has its own landscaping that uses water. Per capita, higher density housing uses a lot less energy and water. On top of all this there's all the driving.
The issue of EVs and apartments is easy, especially for new construction: Add charging stations for residents. If this isn't possible then EV owners can do what owners of ICE vehicles already do... fill up at a station, perhaps while grocery shopping or whatever. Oh look,
apartment buildings in the Boise metro area are already planning for this.
As for solar panels, why do we assume these need to be roof top? My city is nicknamed the City of Trees, so solar panels already don't work well for most homes because there are too many shade trees. Instead, we put large solar farms in the desert. Problem solved.