To add more from madokafc & trishna_amrta, I think the need for it is not there yet to resurect 41 & 42. We are still in the "Minimum" stage which can be translated more to defence part of the equation. Imo thats the main reason, there were talk about SU34 way back then but from our op req perspective the SU30 fill the role perfectly for now.
The "West" is moving toward West made in Europ & West made in US. You know after the Thrump era most European country realize they need to be able to depend & develop their own military industry to reduce their reliance in US products/components, this might benefit us in a long run to avoid ITAR. Russian fighter technology is getting better but wont be on par with the western for the next decade or so. As we know they are starting to market their new SU75 product as "low cost" for acquisition & maintenance, that marketing tag line shows their moving toward maintenance cost reduction & reliability but it is remain to be seen how their product will perform in real world. The future diversification choice of military product will be US version of "West", Europe version of "West", Russia & China