And yet the F-4 with it's advanced avionics, radar, and missiles regularly got worked by the 'inferior' Mig-21.

There's more than simple growing pains at fault here. The F-35 program is basing much of its value proposition on unproven/untested technologies and combat doctrines and is sacrificing a significant amount of kinematic performance, mission capable rate, and deployment & basing flexibility in exchange for these technologies (much like the F-4 sacrificing kinematics & gun in exchange for BVR missiles + combat doctrine which were ultimately rendered ineffective by RoE and the overly optimistic predictions of the AIM-7's accuracy).

By the time all these "growing pains" are worked out and squadrons are fully operational, much of the perceived advantage of the F-35 platform may be rendered obsolete by emerging disruptive technologies and tactics.

This will likely be the very last fighter program of its kind, and I think Lockheed recognized this which is why they did everything they could to plunder as much as possible while this gravy train is still running. When you find yourself in a position where you want to explore other more effective & less costly avenues of modernizing your air power but can't do so (for political reasons) because any such effort would undermine your 'all eggs in one basket' super fighter program that has so far failed to live up to almost every single promise and yet has been deemed 'too big to fail', you know you done F'ed up.

In closing, the F-35 is bad and Lockheed Martin should feel bad.