If this is actually NIMBYs' core claim, I'm overjoyed, because it can plausibly be worked with.
Building literal greenfield subdivisions is a little different from infill/intensification in a city. Where one developer is building all the homes, of course he needs to provide all the infrastructure and amenities between them, or no one will want to live there.
Urban intensification is one site at a time. I hope no single developer is doing so much of the construction that it also makes sense to make him responsible for schools and transit. The whole angle of YIMBYism is to reduce landlords' pricing power through competition. So if ten different developers are operating simultaneously, who pays for what?
If only there were some sort of institution for solving these coordination problems. We could call it... municipal government. If only there were some sort of mechanism for it to skim off of real estate value and use the money for public goods. We could call it... property taxes.
Maybe "our side" isn't campaigning loudly enough for increasing public investements in public goods, but the support is there. What you're probably seeing pushback for is arguments like, "well, I don't see a school in this proposal for 20 condos, so get lost" and other stuff that looks like a rhetorical strategy for a decision you already made, rather than your actual objection.
Road capacity is an interesting one, because people who live in dense walkable environments close to their offices need less transportation. Killing projects in SF based on their traffic/transit impacts sends their potential residents out to Walnut Creek. That's not better.
EDIT: I will also add that huge multi-buildings sites developed all at once have a tendency to feel fake. There's a very real risk of uncanny valley when a developer is trying to bootstrap a neighborhood all at once. Organic, incremental growth is something we should celebrate and encourage.