this is definitely how the game has gone... it does not make it right however imo
un until fairly recently it was possible however to play the game in a manner which kept credits relevant - it has got harder and harder to do as the game went on - however it was not until 3.3 that it actually became impossible without chopping off what to me is an unacceptable amount of the game to play it where credits still mean something.
I think the game needs an economic overhaul and reboot, but I can't see them doing this.
Frontier has an extreme aversion to 'nerfs' or reducing the numbers that players perceive as meaningful. Credits are dead and I don't think they are ever coming back. Frontier will just keep layering alternate pseudo economies on top, to maintain some semblance of progression, without having to take any of the meaningless numbers away from those who have an irrational fascination with them.