Su-30MKIs have technically only been in service with the IAF since 2002-2003. While the development and production contract was signed in 1997, the first aircraft delivered from Russia were only Su-30Ks and Su-30MKs. Some of those were returned, while others (few in number) were upgraded to MKI standards. Basically, the Su-30MKI procurement and growth has run almost parallely with PAF F-16 MLU upgrades and Block 52 acquirement. Due to larger numbers, the MKI project has taken longer.
Also, Derby missiles are just mid-range missiles, not BVRAAMs no matter what they claim.
While Pakistan have certainly closed the gap, technologically and fleet-strength wise, you have to note that India's development plan changed around the early 2000s, when it became clear that the Tejas would not be ready in time for MiG-21 replacements. Suddenly there's a lot of money pouring into the nation, so the MRCA tender was started. PAK FA co-development was approved. Various aircraft upgrades approved and performed. More utility, transport aircraft bought. Etc. Etc.
The focus for the IAF has had to be more widespread than that of the PAF, and also based on a longer timeline. Delays haven't made things any easier, nor where they actually accounted for. So while a comparison between the PAF's and IAF's capabilities are all fine, it is as much due to PAF's accelerated growth as it is to the IAF's controlled growth and unforeseen delays.