If you earn 1 million credits a day for 20 days, you will get 20 million credits in 20 days. If you earn over 1 million credits a day, you get to 20 million credits well before 20 days and it is so simple, so there is no need to increase the payouts.
Really, just earn 1 million credits a day! What percentage of players have the time to do this everyday? It isn't like there is a good menu of events which will reasonably offer interesting ways of achieving this. If you mean rubber banding - are you suggesting that PD set out the game design to include this as a viable way to play the game. Do think the game designers set out to get players to rubber band?
In principle, players who play the game, should be able to complete the game - which includes a reasonable way of obtaining all of the content. I do not considering excessive grinding nor rubber-banding to be a reasonable way to obtain all of the content.
Anyway, I have won a just over 77 million credits since the game was released. I've bought the XJ13. I now have 10 million credits and I suppose the Ferrari P4 is what I should get to provide more variety for the Le Mans race. I have done a little grinding repeating BMB and Le Mans. But generally, i bought the game for entertainment. Mindlessly repeating the same event, in the same OP car to be entertaining. I have a family and a busy job and so when I get to GT Sport, I want to enjoy it. So I do Sport races.
I've entered more than 600 sport races, and have 12 wins. This is because: a. I am not fast, maybe 2 - 4 seconds from the alien times, and b. I find sport races more interesting to start from the back of the grid. When I used to qualify, more often than not I found the race to be frustrating. Either running around not able to catch those in front, but comfortably ahead of those behind. Or, far far far too often, getting smashed into as I was trying all I can not to hit other drivers in the first corner. In sport mode, increasing credits for positions gained sounds awesome - but only if done so without a time penalty. I already am the victim of so much immaturity from other racers.
I think a mix of credits for qualifying position, positions gained and a clean race multiplier based on SR rank is a viable solution. The clean races should based on penalties. Okay, more often than not, when I get a time penalty - I haven't actually done anything wrong. And we can easily point to incidents where it is wrong - but overall, it works more than if we didn't have any penalty system. It should be improved, but players who think that they are anonymous will always try to take advantage, game the system or just act like immature idiots, and maybe even make genuine mistakes.
Having driven over 36,000 miles, whenever a new update comes, I think I should be able to use in-game credits to buy that content. I think I've been active enough to have won sufficient credits to access the new content. I don't think I'm being entitled, I think I've been more active than many players. What is the point of adding content if so few can use it? That doesn't make sense to me?
I also expect that the daily spin would be my friend (actually I think it hates me! - either gifting cars I don't want because I already have 3 of them or at least allow me some benefit. Just how many Group B Fords, Group 4 Meganes does anyone actually need? Please let me sell these cars I get in the daily spin that I don't want. It cannot have been coded to make the player happy (isn't that odd?).
TL
R
The rewards need adjusting. Rubber-banding & mindless grinding should not be required for a very active player.
Increase the payout in Sport mode for racing well.
Amend the coding for the daily spin - increase the probability of winning a car not owned in the players garage, and allow players to sell cars won that they don't won't.
This is a game, it should be designed to be entertaining.