Part of the problem is that the 757-300 was never meant to be a TATL bird. It's range is shorter than that of the 707-320B (3400 nautical miles vs 3800). For reference point, EWR-CDG is 3200 nautical miles. Piece of cake for the 707 but tough for the 753, especially westwards. The 727-200 Advanced that was occasionally and not successfully used in TATL routes had a 3500 nautical mile range.
If there is enough market, and it seems to be, someone should develop a single aisle TATL bird with range well in the 4000s.
*The range of the 752 is close to 4000 btw and the potential 753 replacements 737 Max 9 and A321neo have only 3600 nm range.