And, as I said previously, EVERY house in this area, if not the entire state of Virginia, built since the mid 60s uses aluminum for everything larger than a 30 amp circuit, and I’ve even seen some that used it for 30 amp water heater and dryer circuits.
I’ll take your word for it about VA now. It’s cheaper for sure. In Georgia, I only saw it on feeds and sub panels when I was doing refurbs and installs. And as I stated, at least until around 2000 or so it was that way. Haven’t looked in new housing now, but that, along with other things like plumbing supply lines, water lines in outside walls, would be purchase discriminators for me. It’s just easier to deal with and not have to worry about the potentials noted here: https://codecheck.com/aluminum-wiring/