We are in a era where every single fighter jet is a expensive piece of equipment and also so hyped up that peer powers have been shying away from actually fielding them against a worthy opponent.
Russia-Ukr war was a let down for Fighter Jet enthusiasts with both countries largely staying away from each other's airspace and more aircraft attrition happening on ground than Dog Fights or BVRs
When Turkey shot down Russia's SU-24 back in 2015, Putin opted for economic sanctions instead of retaliating in Air.
US has been on verge of bombing Iran for last 10 years despite having B1s, B2s, F-22s and F-35s in large numbers and Iran being under sanctions for eternity now. It may require a madman like Trump to risk a air campaign on even a beaten down country like Iran
A sixth gen fighter will more likely be hit by a missile barrage when it is parked even before Air combat in our case
For a defensive posture, large number of cheap road mobile long range missiles and UAVs will be lot more effective than a small number of 5th or 6th gen aircraft
We should wait for our economic output to catch up before making huge investments in expensive but fragile weapon systems
We don't even have enough hardened shelters to protect current fleet on ground yet!
In era of every gen - 1st, 2nd, 3rd, 4th, something newer has been expensive.
In all current conflicts the drones are RC (Remote Controlled), not autonomous. 100 drones means 100 operators.
Russia doesn't have anything stealthy up to level of F-22, F-35, B-2. And Ukraine hardly has anything of its own.

But Russia & Turkey will catch up with time on stealth aspects.
We're yet to see a proper war b/w USA Vs Iran. As per latest news the B-2 bombers are gathering in Diego Garcia island for possible strike on Houthi assets & beyond & Iran although still warning USA of retaliation, is pulling out of Yemen, may be bcoz of fear of stealth jets.
Sometimes just the mobilization of supreme assets is scary enough for lagging adversaries.
Since beginning, most jets are stationed NOT in FOB (forward Operating Bases) but outside range of rocket & shell artillery. But R&D has never stopped. To counter such threat & IRBMs, various kinds of Interceptor Missiles & DEWs are being developed.
6gen is aimed to have longer range & also about MUMT, a transition towards UCAV-AF.
Economic O/p to catch up needs absorbtion of population into industry, creating job opportunities. Every future tech creates such opportunities. When making complex platform like fighter jet, the components are not made 1 by 1 but in parallel by their makers. The Govt./MoD is responsible to coordinate b/w them.