I imagine it's of some quality, if for no other reason than the brand attracts talent and the money buys everything the talent needs. That said, what even is educational talent? Is that where the incentives are aligned for the institution, to get the best teaching talent?
As the saying goes: it's not What you know, it's Who you know.
She ended up at Kellogg so still got a strong network, but Harvard is kind of unbeatable.
FWIW I don't think the content changes much between institutions. Certainly I don't see what an Oxford grad learned that some other engineering student at say Imperial or MIT didn't do.
So yeah, you can have much worse education...
In the end the core of a degree is not going to change a whole lot, of course options will be slightly titled towards demand. Everyone who studied engineering did a bunch of math courses and a bunch of physics courses, just like everybody anywhere.