Better yet, how many open WiFi networks are there around your house? For me, the answer is currently 0. People don't leave their WiFi open today like they did 15-20 years ago. Even the wireless hotspot feature on your phone makes you use WPA.
Yes they do. From my 1st WRT54G to my latest AX mesh, I have never had a WiFi password. My friends and family that were visiting over the Holidays apricated it. Everyone used it, no one asked me for the password.
Are people still Wardriving? Even if they are, the odds of a malicious hacker coming to my neighbored is up there with getting stuck by lightning. Not losing sleep over it. Why should I?
2) Access control is exactly the point. I suppose you could ban the TV's MAC address from your open network (and I suppose a sufficiently malicious TV firmware could randomize its MAC address), but your stated purpose (allowing open network access) is not exactly compatible with what you presumably wish to do (disallow network access to a smart TV).
I run an open access point and depend on tls or ssh to protect my traffic.
There are a dozen good reasons why every piece of consumer grade networking hardware released in the past 15 years is not configured this way by default.
And there is precedent with Apple for example using everyone's phones to send airtag location data (enabled by default), or Xfinity / Comcast opening a second SSID (hidden or not) if you use their modem / gateway combo.
You don't need to have any of those things, it's enough that your neighbors do for future "unconnected" smart TVs in your home to piggyback on.
There's been a bunch of gnashing of teeth about how they'll connect to open WiFi networks, but I can't remember the last time I came across a public WiFi network without a captive portal that would block their attempt to phone home. That seems to have died off in the last few years.
And if you're prone to tinkering you can just as easily connect one through an SBC and block all traffic