I'm also not convinced there needs to be a direct replacement for the Su-25 (or the A-10, for that matter).
What does this kind of aircraft bring to the table that a combination of armoured combat helos (i.e. the type Russia favours with the Mi-28M and Ka-52) and MALE UAVs can't provide as well or better these days? The main advantages of a ground attack jet over helicopters used to be range and time to target, but no matter how quick the fast mover is it'll still take longer to respond than continuous UAV coverage that is already orbiting in the area. Survivability against trash fire is not all that much better than a helicopter (Russia managed to lose a Su-25 to rebel ground fire in Syria) if the helo has good ballistic protection and decent countermeasures, while at altitude anything better than a MANPADS will take it down just as easily as a MALE UAV.
Ok, payload remains better than either of the alternatives, but that's far too narrow a niche to justify the cost of anything more bespoke than a Yak-130 derivative.
What does this kind of aircraft bring to the table that a combination of armoured combat helos (i.e. the type Russia favours with the Mi-28M and Ka-52) and MALE UAVs can't provide as well or better these days? The main advantages of a ground attack jet over helicopters used to be range and time to target, but no matter how quick the fast mover is it'll still take longer to respond than continuous UAV coverage that is already orbiting in the area. Survivability against trash fire is not all that much better than a helicopter (Russia managed to lose a Su-25 to rebel ground fire in Syria) if the helo has good ballistic protection and decent countermeasures, while at altitude anything better than a MANPADS will take it down just as easily as a MALE UAV.
Ok, payload remains better than either of the alternatives, but that's far too narrow a niche to justify the cost of anything more bespoke than a Yak-130 derivative.