I wonder if part of it is horribly cheap flash storage used in smart TVs, after a bunch of update cycles, telemetry upload/downloads, etc. etc. I wouldn't be surprised if the flash chips might be wearing out and take longer to read/write to.
That or the TV companies are intentionally making previous TVs slower with updates they know old TVs can't run with any modicum of speed.
That or the TV companies are intentionally making previous TVs slower with updates they know old TVs can't run with any modicum of speed.