I don't think that the OP was talking about the cell network changes when they said that the phone had lost support. GNU/Linux phones (Librem 5 and Pinephone) will never loose software support, since they run mainline Linux. Also, Librem 5 has a replaceable modem.
Oh, Purism. The guys who included a separate chip to deny the user the ability to upgrade the firmware, so that they could meet FSF's completely arbitrary requirements for a honorary badge of freedom (see the hypocrisy?), but neglected an IOMMU, so the baseband (or any other device on the bus) can wreak unlimited havoc (see the irony?). Great alternative indeed.
> neglected an IOMMU, so the baseband (or any other device on the bus) can wreak unlimited havoc
The Librem 5 doesn't need an IOMMU, because it uses separated components, and it uses serial buses (USB 2.0/3.0, SDIO, I2C and I2S) that don't allow direct memory access, so there is absolute no chance of the WiFi/BT, cellular modem, GNSS and USB controller being able to access the RAM or the SoC's cache
The USB URB structure have a field named 'dma_addr_t transfer_dma',
used for DMA access. I've abused that to chain vulnerabilities. To boot, it is possible to develop an I2C-B2C or SPI bus master which is capable of DMA toward the host memory. Linux 2.5 kernels and later, USB device drivers have additional control over how DMA may be used to perform I/O operations.
Do any of these guys actually read the hardware specs or do any real hardware hacking?
I don't know, Google integrated the mainline Linux kernel a while ago. Probably most of the modern ones.
PostmarketOS fills the plaything niche like the Librium 5 and pinephone do but much cheaper with much better old hardware. Aside from a checkmark of running the latest kernel and hardware switches what can the librem 5 do an Android phone can't do much better? They aren't good phones.
Lifetime updates, no proprietary drivers, support of tens of different operating systems, schematics, openPGP card, desktop apps and convergence, verifiable security.
Those are features but not descriptions of good uses. Running a small laptop or steam deck fulfills all of that and much more and I've yet to see an instance where it's a good use. Again it sounds like a plaything to tinker with, with no real world use as a phone or computer.