Did you ever seen an intercom or IP camera with macsec support?

yes

for example https://newsroom.axis.com/en-us/press-release/macsec-zero-tr...

That's great.

Now we need to get an enterprise grade switch - doubt Cisco would add macsec into SOHO gear. Along with enterprise grade intercoms, cameras, doorbells...

And beloved by many Unifi is out of question - they still can't bake IPv6 support.

So looks like it's feasible but the cost wouldn't be good.

ADD: also read this article: https://news.ycombinator.com/item?id=41531699

i well familiar with macsec. we use it between datacenters and for aws directlink. it de-facto standard for this kind of stuff. i even worked on hardware that provided macsec support

a couple of years ago I tried to use it inside datacenter during fedramp implementation. it crashed and burned for a couple of reasons:

- linux wpa_supplicant was crashing during session establishment

- switch had a limit on number of macsec session per port