Did I say that the Rafale was a bad purchase for India?
India gets access to some of the best 4th generation technology and can also fill in the numbers gap in it's air force squadrons.
My point is that the Rafale would not be competitive to some aircraft that could very potentially be inducted into the air-force of neighbouring countries in the next decades.
I am sorry to say but some very reasonable Indian posters are not being objective at all about the Rafale.
Yes it is a great fighter but at the end of the day it has a massive RCS when compared to any 5th generation fighter out there currently or due to be inducted in the future.
Engines, radar and avionics can be upgraded but the airframe will pretty much stay the same bar some minor modifications.
In BVR scenarios it will always be at a disadvantage as the other fighter will get first look - first kill option on it. Again not saying that the Rafale will be always shot-down but it will have to survive the volley of AAMs coming at it before it can engage the other fighter.
But rafale will still be able to bomb ground targets, give close air support, drop laser guided bombs, drop nuclear bombs, strafe infantry and vehicle columns with cannons or rockets, and a lot more things as effectively as a 5th gen platform, while being much cheaper than a fifth gen platform. Aerial warfare is not all about air to air combat, these are multirole aircrafts that perform a lot of missions, and shooting down other aircrafts is just one of the missions. And it will still be able to fight down non stealthy fighters of the opposing air force - and the enemy will have plenty of those, unless the enemy is USA.
If your only point is that rafales cant shoot down stealth fighters in a one on one engagement, you would be right. However, it can do 99 other things, which is why Indian members here are saying that it will remain relevant for 30 years.
Also, air combat won't be that simple either. Rafales can still be part of a mixed formation with PAKFAs (for example). The 5th gen ones can fly well in front, detect incoming 5th gen fighters while rafales stay too far behind to be detected by the enemy 5th gen fighters. The radar data of the PAKFAs can be shared with rafales, which can then shoot missiles at the enemy while being behind radar range. There are a lot of tactics that will be employed to make 4th gen fighters useful in air warfare, just like there are lots of tactics employed currently to keep 3rd gen fighters potent in aerial combat.
Look at how the IAF uses MKI and mig-21s together in air combat. The mig 21s stay behind the MKI, which detects incoming fighters with its huge radar, while the mig 21 is too small to be detected by the enemy at that range. Then the MKI as well as 21s shoot BVR missiles. There are several operational tactics, it is not simply going to be a one on one engagement. So it is not what you see on paper - 5th gen, low RCS, hence they win. No, it wont be like that. A few 5th gen and a few 4th gen ones will fly together and share data.
Tactics will evolve for each type of mission, depending on the available aircrafts and their capabilities. The IAF's job will be to find innovative tactics to keep their aircrafts relevant. That's what the planners in all air forces do.