Which one(s) would you suggest for little DIY things like home automation, print servers, etc?

If you want a true SoC because it's tiny and cute? Try a TI Sitara (BeagleBone, etc). The new BeaglePlay is really nice for $98.

If you need a home automation/print server? Get a $40 used Xeon workstation on eBay.

I don't know much about RPI alternatives, but those seem to either cost a lot more (BeaglePlay) or they seem to be much larger and with worse power consumption (used Xeon workstation)?

Then you're stuck. If you want to wait for the cheap subsidized part then it might be a while. Maybe forever in the case of the original Broadcom SoC. Beaglebone Black is ~$50 if price is really the problem. What's your objective here?

ESP32-S3-DevKitC-1 v1.1 is excellent. It's got multipurpose GPIO pins that can be used for input, output, ADC, touchscreen, etc., and it's got wi-fi and BLE. Easily programmed with the Arduino IDE. It's an MCU, not a single board computer. If you really need a Linux environment then Orange Pi has a lot of SBC models available. For those I use Armbian, which is optimized for SBC use.

How many of them run mainline Linux?

FSL/NXP is on 6.1.4 and TI is on 6.3-rc2. ST seems harder to find, they look like they're merging 6.3. Is that close enough?

I think so, thanks.

Last time a looked (which was a long time ago), most other SoC's led you down hyper-version-specific patchy nonsense to Linux to run on them. Good to see the field is improving :)

Getting mainline on their Yocto recipes is tough, those tend to lag way behind. But anything is possible if you bang your head against those recipes hard enough.

There are other SoCs, but none has anything like the vast, vast, vast ecosystem of tutorials, videos, packages, and accessories that Pi has developed over the past decade.

...everything except real technical documentation on the part, which Broadcom won't give you.

Oh yeah, and you can't actually buy the part alone. So you're stuck buying their board to stick in your project.

I believe most of people would be just fine with NUC.

My uninformed impression is that while Raspberry Pi's have all but disappeared from the marketplace, Orange Pi has grown with more models and availability.