True and it's worse with trade-ins for those who don't want to deal with the hassles of selling privately.
This is why recently, I just run my iPads into the ground. I used my 2017 iPP 512GB for 4 years and the 2021 M1 iPP 1TB will break that record.
I hate selling too, but sometimes it's the best solution, other times I just never sell.
It's always a dilemma. Buy an overspecced device and run it to the ground for a decade or just "embrace obsolescence" as some suggest and get a new one every couple of years, with a new battery, new features etc. without getting the top of the line.
I have kind of gone different directions over time. For the smaller size I go with buy on a deep discount a couple of years after launch (I got my 2018 11" 1TB 4G at 900, instead of 1700 in late 2020 and my 2TB 5G M1 11" at 800 in early 2024), and I plan to do the same with the M4 or M5, will get the 2TB 5G once I can find one under 1000. And I never sell the small ones, I use the older ones as "Apple care+" in situation where I don't want to risk my newer devices (currently my AC+ iPad is the 10.5, will be replaced by the 2018 in the future). So I run them to the ground.
With the 13" it's harder, you don't find those offers as easily and you generally need to go used for those top of the line models. Or spend a fortune and run them to the ground. But then Apple gets me with something I absolutely want, like the ultra-light M4.
Or some features like external monitors that the 2018 didn't get. You are in a very unique position where the 16GB M1 is extremely future proof and got all the features and has as much RAM as even the M5. So if you are ok with the weight, you are good till the end (you choose if the end is the last year of support or a couple of years later).
And if you are ok with the battery not being what it used to be (because good luck having Apple accepting a battery service)
But knowing myself, I knew that in a few years I'll probably want the M7 or M8 and the loss I'll make on my M5 will be much less than if I buy the 1TB cellular.
I try to never spend over $1500 on a tablet (the max I have spent was little mode than 1400), and that's very hard to do with the 16GB 13 models, unless you go used (which is what I have done with my 12.9)