I haven't noticed any change for anything that I do on my iPad since installing 16. I don't do much on it though.
I have found myself using my 11' iPad Pro III a lot more since I installed macOS 13 and iPadOS 16. Cross-platform capabilities such as the ability to use the macOS keyboard and trackpad to control the iPad and automatic sharing of internet connections make it attractive to use the iPad as an adjunct to my Mac. Add to that its utility as a stand-alone utility device with true multitasking and the availability of "industrial strength" applications and I more and more often find myself using my iPad in preference to my Mac. By-the-way, although I have not heard or read anything about it, it seems to me 'Scribble" is either noticeably improved in iPadOS 16 or my handwriting has dramatically improved.
Age?...per joemike's advice about needing the latest hardware for some stuff. Anyway, we're like you....haven't been doing a lot that matters, although I will admit to an interest in the Apple pen functions.
Some features, like "Continuity Camera", satellite communication, and accident detection and notification require new hardware features on the iPhone and Apple Watch
; those are pretty remarkable, but seldom used. The pen is IMHO essential
, but for maximum effectiveness you also need a screensaver that offers some drag and a softer tip than the one that comes on the pencil. Fortunately, both are relatively cheap, but I went through several of each before I found a combination that has the right feel