I was trying to buy a new tractor over the last few weeks, a neighbour wanted to buy my 12yr old MF6490 and I have to upgrade my plough, 14 yrs old.
The reasons I was looking at changing were, I wanted very new tech wheels and tyres (IF/VF 650/65/42's & %40/65/30's), I wanted auto guidance, I wanted a new lift (trusting a very heavy implement on a well used 12 yr old lift gets more and more an act of faith). I could have retrofitted all the above to the 12 yr old tractor and repaired to like new, but it would have cost close to €30,000.00+V and I would still have a 12 yr old tractor and still would be hoping nothing fails with the very heavy equipment on the lift.
I didn't end up buying new as the gap between new and the 12 yr old is too big for me to bridge even though I almost bought a NH, so ended up with 1 yr old.
For me what new tractors offer over 20 yr olds is as follows.
Properly integrated tech.
A choice of good 200hp tractors that are a manageable size, the only 20 yr old tractor anything like that was a JD7810 and it really wasn't supposed to be 200hp.
10 ton lift capacity and the reassurance that it is new.
Unfortunately the price is getting way beyond agriculture's pocket, as I said to the salesmen the problem is the price of our commodities, all farm produce would have made as much or more at some time in each of the last 5 decades. Our buying power is shrinking and we give that everyone else expects a living wage.
Not having a go at your thoughts
@AYF for a stockman tractor very little has improved and a lot has disimproved, just my thoughts from a tillageman's point of view.