Why didnt Warpac states adopt MiG-23 en masse and still relied on MiG-21 by 1990?

I’ve always been amazed at how obsolete the fighter fleets of non-USSR Warpac states were.

In 1990 their mainstay fighter was the MiG-21, usually in MiG-21MF model with some MiG-21bis and older MiG-21F-13/PF/PFM still in service.

MiG-23 air defence versions were adopted in quite low numbers when compared to MiG-21:

Bulgaria – 42 MF/ML/MLA/MLD – about 1 regiment’s worth. Second regiment had ground attack BNs.
Czechoslovakia can’t find numbers, 105-150 but not sure of split between AD and ground attack versions.
East Germany -75 MF/ML – about 2 regiments worth. Second regiment had ground attack BNs.
Hungary – 16 MF/UB – single squadron
Poland – 42 MF/UB – again a single regiment
Romania – 46 MF/UB – again a single regiment

It’s not that uptake of MiG-29 was high either:

Bulgaria – 22 a/c
Czechoslovakia – 40 a/c on order, 20 delivered, 20 cancelled
East Germany -24 a/c delivered. 2nd order of 32 a/c was cancelled
Hungary – 0 (28 delivered after 1990)
Poland – 12 MiG-29 delivered
Romania – 18 MiG-29 delivered.

MiG-25 was not adopted at all except some Bulgarian ones for recce.

So why didn’t Warpac members buy more MiG-23s instead of relying on MiG-21 which was proven to be easily countered by F-16 over Bekaa Valley in 1982? Indeed in 1970 Soviet pilots flying MiG-21s were thumped by Israelis flying Mirages and F-4s.

And if Cold War had continued, would we still be seeing MiG-21 being used en masse by Eastern European states?