You're missing the point. The useful thing is to run some service on the LAN, be it a web interface for a NAS, a web interface to control some lighting, a web interface into a media PC to do remote desktop type stuff or control media playback, a debug interface into some embedded product I'm working on, or a whole host of other things. The thing that makes web technologies useful for this is that it Just Works, from any other machine on the LAN (my laptop, my phone, a guest's phone, etc).
By making technologies available only in a "secure context", they're blocking them out of this whole category of use cases.
You can get a free cert from letsencrypt using their dns challenge. No need to expose to the internet. Add a DNS record that points to the address of your LAN and it’ll make things even easier for your guests.
Before RPI existed, I always made filesystem images for USB sticks in NetBSD so that writes never touched "disk" ("diskless"). This allows me to remove the USB stick after boot, freeing up the slot for something else
BSD "install images" work this way
I have been using the RPi with a diskless NetBSD image since around 2012; there are no SD card writes, the userland is extracted into RAM
I can pull out the SD card after boot and use the slot for something else
If I want data storage, I connect an external drive
It's been wild to read endless online complaints from so-called "technical" RPi users for the last 13 years about SD card wear and tear
To me, it's another example of how it's possible to have a solution that is as old as the hills and have it be completely ignored in favor of a "modern" approach that is fatally-flawed