With rocket fighters you need bouth secret lab and aircrafts factory when for interceptors you need only aircraft factory witch is used to produce every other unit from airforce resrch branch.
If you use secret branch units, yes rocket fighters would do the job, buth if you dont, that is exclusive expense.
And you cant just wait untill day 5,there is a chanse that you would incountere enemys with airforce before that. Alsoo range difference isnt small and carrier based aircrafts are mutch more usefull if playing some nations like USA or UK.
It is well balanced and it is not "broken" or "op" if it axually can be used in one doctrine as in every other doctrine it is next to useless.

Have you checked the defending/attacking stats? If defending rocket fighters will be destroyed.

Also how often have you seen a player using rocket fighters? Making enough airbases for a rocket fighter is a pain in the neck.

Rocket fighters have a small range so you can't put them in a stack with your attack or tactical bombers.
Rocket fighters can't land on a carrier so on a map like the 100p World at War or 50p Pacific that poses a big problem.
Rocket fighters for me are an additional force that i keep ready as a shock force to attack juicy enemy bombers.

The minimum production time on a rocket fighter is 21 hours. For a lvl 5 interceptor it is 7 hours

Soo we all agree that rocket fighters arent overpowered rather underpowered, right?

Anyone barely ever uses rocket fighters as such a short range so u need to build so many airports it's not really a resource advantage I don't think the timing of research or anything will change it

If you ask for my honest opinion, I agree with you that they are unbalanced. They need a buff
As Axis they are a good option, questionable as Allies or Comintern and suck in every possible way as Pan-Asian.

Please note I'm talking of real "competitive play" between pro players, not just normal maps where every "joke strategy" like flying bombs or heavy tanks can work.

You aren't factoring in that Interceptors research and production are necessary for your airforce early before rocket fighters become available. This means that the research costs of lv1-lv3 Interceptors should not be factored in, as we're talking of "whether or not to switch into rocket fighters".

The cost of Interceptor lv4, lv5 and lv6 is 6,350 goods, 6,350 oil, 9,450 rare materials and 29,150 money.

The cost of the aircraft factories isn't factored in as you already built them for bombers and air transfer anyway.
You may need a couple more air factories but also keep in mind the short range of RF means you need way more airstrips for proper air transfer.

The cost of flying bomb, rocket fighter lv1 and lv2 is 2,850 goods, 6,200 oil, 8,800 rare materials and 17,850 money.

Before celebrating how cost-effective that is... you also need secret labs (and high level ones) which means you have to start building them quite a while before rocket fighter becomes available, holding your production and economy back.

It wouldn't be wise to rely on rocket fighters only and assume it will work. When you're defending they're great, but the only reason someone's defending is they want to resist, counterattack and win. In competitive play, using rocket fighters for offensives is rare to see and almost always fails.

Rocket fighters only have 300 range at level 2. Could it ever be easier to snipe the airport and destroy them all? Likely not. Keep in mind RFs cannot scout so you're blind to stealth attacks, unless you also bring your raiding units there to defend - when those could be sneaking around, destroying enemy economy, picking off reinforcements or keeping your enemy on the defensive.

And if your airports really get sniped (raiding units, rockets or just a fast assault when you're offline does it with ease) you may end up losing the whole airforce, not just the rocket fighters. Interceptors have way more range so they will be fine there.
This means that even if you switch into rocket fighters, you need Interceptors. In competitive play you can rely on only Interceptors, but can't rely on just RF, you need Ints still. Int scouting ability can also change games pretty often, and you can't land RFs on carriers, so you'd have no air superiority on water.

The short RF range, the need of densely placed airports and upgrading airports to minimize the risk of snipes means you can get paratroop rushed. Rare strategy to see though...

Aircraft is especially important on large fronts. Even if you're defending, but it's a large front, guess what. RFs only have 300 range compared to 500 on Ints. When a sneaky assault comes in, you need the RFs to be within 300km compared to 500km for the Interceptors, meaning you need to place RF wings way more densely than Int ones.

The need to cover the front means you have to spread out the airforce a bit, often ending up with less than 10 fighters per army. As Interceptors lv6 are cheaper, they get an advantage there - unlike 10+-stack fights, there having more numbers gives you more health AND more damage.

Considering rare material cost (as lots of airforce means you'll lack that) there will be 4 lv6 Interceptors per 3.3 lv2 rocket fighters.
Now multiply the damage by the health (Allies doctrine used) 228*100 (Int) vs 188*105 (RF) and we find out the rocket fighters will lose. Now keep in mind those are lv6 Interceptors... in competitive play players will often have lv7.

For lv7 it's 2.02 Interceptors per 1.9 RFs. That's 108*89=9612 (RF) against 151*65=9815 (Int).
But this time I was using Axis, the doctrine which has RFs buffed, and still, the Ints ended up more cost-effective.

As I don't like to torture joke strategy users with statistics, I won't continue with Pan-Asian who have Interceptors buffed.


Exactly... I can't even justify building RFs as Axis. Not mentioning other doctrines which don't have the RF buff