I have a phone with no sim that I use sometimes over wifi, but I have another one with a sim that I sometimes use as a wifi hot spot for the no-sim phone.

I use phones without Sims, but it's because I'm cheap and I have a collection of weird phones.

My kids have phones with no SIM card; they can call 911 and they can use WiFi when in range; I have them set up with a VPN to home, so that’s the only connection any hotspot sees.

You can call emergency services even without a sim, so you might not be as disconnected as you would think

A SIM card only gives you cell phone service. The cellular modem on your phone still connect to towers you're still tracked by your IMEI, you can still make emergency calls, your phone is still pinging towers, you're just making things inconvenient for yourself

That's a strange argument, why do you and lots of people replying here believe they are NOT tracked over WiFi which are themselves relying on ISPs?

If you don't trust your ISP why would you trust random ISPs more?

I have a Pixel 7a with GOS in airplane mode, with WiFi only. My old phone with the sim inserted is on Lineage OS and hasn't fully (has a case of occasional ghost touch) died yet. I only use the old phone for cellular telephony.

No I have people I want to be able to contact me.

I have a data-only sim, otherwise no sim for phone calls. My phone stays in airplane mode nearly always. I use voip to make and receive calls when wifi is an option. Most voip providers, afaik, are not privacy respecting including the one I use. Planning on switching to jmpchat someday which is all about privacy.

i have my boss's old one here that's pretty much only used for testing mobile web and for its camera. i use a 'dumb' phone, and its camera doesn't work (was crap-tier anyway when it did). i think it has 10 on it. it doesn't leave the office, doesn't get used that much, and has no google account linked to it anymore since it was totally reset when it was replaced earlier in the year.. the inability to use google play to install a few apps reduces its usefulness. i got f-droid on it but not everything is available from it.

If I had to go WiFi-only, there would probably be hours-long gaps when I am unreachable. So my compromise is to use a non-KYC data-only SIM. Even if VPN is left off, it routes traffic first to a datacenter far from my actual location, and there is no longer a route for unencrypted calls and SMS and the associated spam. I don't have a habit of streaming media on the go, so the data lasts quite a while and there isn't much of an urge to use public WiFi.

Doesn't fully eliminate the problem as IMEI is still sent and the cellular modem is still a rogue black box, but a step in the right direction. Knowing that the cellular modem can run whatever code with deep privileges as it wishes, I try to keep as little of my business on my phone as I can, with the bulk of my workflow centered around my laptop. Don't get me wrong, I don't think this automatically makes me immune, but I do think it's a neat little exercise. Perhaps one could abstract the problem of the modem by getting a separate wireless hotspot.

My friends and family have accepted that they either need to get Signal, XMPP, or Matrix or I will be largely unreachable. The only remaining need for SMS and GSM voice calls stems from work, which is all handled by my work phone that is powered down, or at least disconnected, once I leave for the day. It sucks that this is not the norm, but it looks like I am quite fortunate that my friends, family, and employer all tolerate this workflow.

Take a look at "IoT" SIM cards, they're a bit expensive and data-only, but might not be subject to the same KYC regulations.

When I got a new phone a while ago, I put my sim card in the new phone and kept using my old phone on wifi only.

I did for awhile but it was stock android and I was not doing it for privacy reasons. I just see no reason to pay for something I don't particularly want. I use a talknow sim currently but mostly use it on wifi.

I do have a SIM card for emergencies but I keep it on flight mode 100% of the time.

I tried, but could never find anything that would work as a VOIP subsititute. So now I have a pixel that does everyrhing except phone calls. Getting close to just giving up and slamming a sim in it because at least it's a little better than stock android.