The old springers - HW80, Feinwerkbau Sport etc are as good as the new ones of the same type. The quality of the pellets has been the main thing in improving accuracy. The sliding breech made popular by the HW77 was really the end of the major development of the springer, any improvements past that are really just tweaks. Modern tuners have a much better grasp of what is going on in a springer, so they can be far easier to shoot than the old school set ups.
I think the TX200 is probably the represents the end of the line for the spring powered rifle in terms of accuracy, the recoilless version was not actually any more accurate, just a tiny bit easier to shoot.
Future developments will have to be on improving lead-free ammunition so that it is as accurate as the lead stuff, and maybe some kind of active recoil damper if people can be bothered to pay for it, which they won't as they can buy PCPs.
The springer is at about the stage that the Mauser rifle got to in the 1930s, about as far as it could go in development. New Mauser rifles are still being made, so its not a bad thing.