Tu-204 is the only manufacturer left in the 757 niche, or what is left of the niche. And they are developing the Tu-204SM.

The TU-204 gets no where near the 757 except in the number of seats they’ve crammed into it.

But B707, 727, 737 and 757 use the same fuselage, which dimensions were set in the late 1950ies. It was OK back then, but airlines demand more today. The B757 was a good aircraft, but sales don’t lie and the fact that the single aisles cashed it big sales while the B757 was discontinued speaks for itself.

Rose tinted tosh.
Why are you comparing it to the 737/A320 sales to justify your argument?
We all know the 757 cannot be compared to them in that way. It was not designed for the same markets. The 757 was designed to replace the 727 and it did that.
Sales do not lie, that is very true. So you must concede that with nigh on 1000 units sold, I think the 757 proved it was the right aircraft at the right time for the right market.