Why will IAF will not upgrade Su30?? One can abuse Babu or Baby but we are not that stupid we can't ignore such a valuable assets. we Certainly upgrade 30 mki
Su-30 has upgrade deal has been hanging since 2010 because of unavailability of 
And after this corona hit,
no chance for next 5-7 years, we won't even have money to buy MMRCA!
IAF is apparently planning to retire atleast 50 older Su-30 post 2035, may be replaced by ORCA as bomb-truck for CAS or interdiction. Deep upgrade required may cost as much as whole new flankers, so they decided to get a cheaper to operate, easier to maintain, more available, less fuel-guzzling jet.
Single engine or double engine things are bullshit ( some exceptions ). Capabilities matter more
A twin engined larger version of MWF is significantly more capable, on the fields of either payload & range (like Tejas Mark1 compared to older F404 powered Rafale), or by pure thrust (Jf-17 vs Mig-29).
But now that you've dismissed the whole operational doctrine of IAF & IN as baseless, that leaves nothing more to be said... No point fantasising on improbable scenarios.