| Why do you think, that they were not? Problem was, that rocket bombs were too heavy and cluster-bombs (or rather - cluster containers) used by Il's were not suited for fighter planes (amde from wood). Both LaGG and MiG could carry 2 FAB-25/50/100 bombs (one under each wing) and rockets (usualy three or four 12,5 kg RS-82 under each wing). Yak-1 was exception and only from 43. series it had pylons for rockets or bombs. But then most of them was demonted in the units - fighter was too slow with them).
There was even fighter-bomber version of Yak-9 (Yak-9Ł), with internal bomb-bay for four bombs (usually FAB-100 or 4 PTAB containters with 32 PTAB-1,5 bombs each).
From all standard version of russian fighters only Yak-1 till 43.series, all Yak-9 (with exception of Yak-9Ł) and Yak-3 were nable to carry bombs or rockets.
Not to mention that to use most of small russian bombs effectively, you had to use then en masse, so using fighters to drop them, when you have dedicated attack planes is waste of resources. Not to mention that Russians believed, that if one had to use fighter for anti-tank mission, then big gun (37 mm, but they have exeprimented with 45 mm) is enough for most german tanks. Remember, that germans were still using lot of Pz II and Pz III tanks or based on them tank-destroyers, so 37 mm was more then enough.
Drop tanks were a) not needed (as most of actions were above front and fighters never needed long range) b) waste of precious resources (aluminium).
When Russians decided, that they need some long-range escor fighter, they've made one from Yak-9. Yak-9D and DD versions were long-range escort fighters, simmilar to Mustang or P-47N. DD version had even simmilar range (2285 km) as Mustang and endurance of 6,5 hours.
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