Fundamentally I guess it feels like they have ground to a halt or even quietly retired the DSM line.
Let's look at your NAS for an example (it's actually worse for mine cause I always loved the Slims lmao).
DS1821 has no GPU transcoding because it uses the AMD Ryzen 1500B, what you've observed is this processor is just powerful enough to brute force some transcoding but it has no hardware transcoding:
https://www.synology.com/en-global/products/DS1821+#specs
DS1821 successor was recently revealed to be the DS1825. So if your NAS died in a few months, that would be your obvious choice for a replacement. They decided to continue using the AMD Ryzen 1500B, which is now seven years old. TBD if they bother releasing it this year. In a few months they could call it DS1826 instead.
https://nascompares.com/2025/03/13/synology-ds525-ds1525-ds4...
Meanwhile DSM still lacks support for NVMe volumes, in fact there are still no NVMe-only models at all, you can't even install DSM to NVMe, they cut support for USB drives, they cut support for HEVC, and they almost never update docker and some of the other tools.
The hardware's going nowhere and the software's going backwards.
