Is it just me or does that seem really scummy on the part of the company??

No scummier than a candidate that's not seriously interviewing for a job, and is instead just fishing for counter-offers.

That worked in 2012, but I highly doubt it would work in 2023.

Why not? If you’re truly willing to walk away from an offer, non-negotiable ones often turn out to be malleable.

You will just walk away, and another from the large stack of candidates who passed the interview process will accept that same offer. Engineers just have become much more easily obtainable and replaceable.

Not in my experience ¯\_(ツ)_/¯

Just to make sure: nit in your experience in 2023?

Engineers with a bunch of hard to find skills are still hard to find.

It might work in 2024, or 2025, if the market improves, though.