"Business decision" and "artificial limitation" are frequently synonymous. I think @MishaalRahman was correct to say "If OEMs keep buying a particular chipset [...] then it'll continue being supported", especially with Qualcomm, if the sales volume remains high enough. I also agree it is generally correct to say you can pay an SoC vendor to continue supporting a chipset, but that doesn't seem to have been correct for Qualcomm.
If a particular mid-range chip was still selling well years after release, then Qualcomm may have seen fit to continue supporting it so that those new phones could continue selling well. Qualcomm primarily cares about selling chips. Supporting old chips that have already sold (and aren't continuing to sell well) does not help Qualcomm sell more chips, so they haven't wanted to do it. I think Qualcomm may come around to supporting chips better (maybe even at their next announcement in a few days), but their historical behavior in this regard has been less than ideal.
In fact, Qualcomm cares so much about selling chips that they've allegedly nearly sunk the Oryon SoC in the process.[0] They apparently saw an opportunity to force-bundle more chips, in this case the PMICs, which were so unsuitable that the manufacturers wanted to buy them and literally throw them in the garbage just to keep Qualcomm happy, while using alternative PMICs instead. But, Qualcomm supposedly baked the decision into Oryon so deeply that only Qualcomm's PMICs are compatible. Apparently, this is causing manufacturers to consider abandoning Oryon entirely. Most people would logically think that Qualcomm cares primarily about making money, but instead their first priority actually seems to be selling chips, even if it means leaving money on the table, regardless of whether that is logical or not.
Why did Fairphone choose to use an industrial SoC if they could have just paid Qualcomm a little more money to extend the life of the Snapdragon 8 Gen 2?
Qualcomm is happy to enter a support contract for the BSP they provide. It will be frozen at that already-outdated LTS kernel with whatever mainline backports they feel the need to apply, and the drivers will be the same binary blobs shipped on day one because Android HAL.
This, understandably, runs into Google's CTS policies regarding minimum kernel versions and others, which is why 2 OS releases + 1 year security became the norm.
Still, Projects Treble and Mainline just reached the point where you can stick with 5.x kernels and have an extended support schedule. This involved revving the HAL interfaces among other changes that are just not (economically) feasible to backport. OEM BSPs that are derived from Android Common Kernel releases can feasibly be supported for many years; for example, 5.10 shipped to AOSP in 2021 and will be supported through 2026 [1].
If a particular mid-range chip was still selling well years after release, then Qualcomm may have seen fit to continue supporting it so that those new phones could continue selling well. Qualcomm primarily cares about selling chips. Supporting old chips that have already sold (and aren't continuing to sell well) does not help Qualcomm sell more chips, so they haven't wanted to do it. I think Qualcomm may come around to supporting chips better (maybe even at their next announcement in a few days), but their historical behavior in this regard has been less than ideal.
In fact, Qualcomm cares so much about selling chips that they've allegedly nearly sunk the Oryon SoC in the process.[0] They apparently saw an opportunity to force-bundle more chips, in this case the PMICs, which were so unsuitable that the manufacturers wanted to buy them and literally throw them in the garbage just to keep Qualcomm happy, while using alternative PMICs instead. But, Qualcomm supposedly baked the decision into Oryon so deeply that only Qualcomm's PMICs are compatible. Apparently, this is causing manufacturers to consider abandoning Oryon entirely. Most people would logically think that Qualcomm cares primarily about making money, but instead their first priority actually seems to be selling chips, even if it means leaving money on the table, regardless of whether that is logical or not.
Why did Fairphone choose to use an industrial SoC if they could have just paid Qualcomm a little more money to extend the life of the Snapdragon 8 Gen 2?
[0]: https://semiaccurate.com/2023/09/26/whats-going-on-with-qual...