Will a New Amp Sound Better Than My ML333?

I have a Mark Levinson No. 333 amplifier that we bought new over 25 years ago. It was repaired by an authorized service facility 5 years ago. I do not know whether the facility performed any restoration beyond the needed repair, which was fairly extensive. The ML333 is my main amplifier today, as it has been since we acquired it.

Anyway, I generally believe that new technology is better than old technology, so I have been wondering whether I should consider replacing the ML333.

Will, for example, two Benchmark AHB2's in mono mode, or a Bryston 4B3 offer a sonic improvement over the ML333?

If I "upgrade," the amp must have the possibility to be the last amp that I ever buy and must not restrict my possible choice of speakers in the future.