I currently have an old Sony STR-DE898, and I’m debating whether it’s worth upgrading or not
Absolutely not! Take any $$$ You were planning on sinking into the Sony and put it toward an Anthem AVR. Their newest MRX 540 is $1699, but as you obviously don’t need the latest bells n whistles here’s a nice used MRX 520 that was the previous model and can be had for only $750 and will smoke your Sony on every level.
https://www.ebay.com/p/5020630793
Best of luck.