GT5 is easy when you use an overpowered car against your opponents. Try a fair play game and see how things come up!
I did. I decided to give the AI a fair shot at giving me a good race. I knew from the beginning that it wouldn't be close to an online race, but the results were ever more disappointing than I thought. Took a fresh from UCD 97 Tom's Supra into the Super GT. No oil, engine, or chassis. To make things harder, I went to Fuji, where the lack of hp would hurt the most. Unsurprisingly, the AI flew by me at race start, but by the first turn I had made it back to maybe 3rd place. The prodigy car for that race, the Xanavi Z, was already leading and had a gap, which made the other 14 AI cars redundant. By the end of lap one I was basically ready to pass him, but when he got to the straight he pulled away. I think the second place car caught me too. But again, going into the first turn I get a massive gain, and get back into second. I proceed to eat the Z alive for the rest of the track and am leading by lap 3. It ceased to be a race then.
GT5 is a game where it's more challenging to make the AI difficult than it is to beat the AI. Using a fair car isn't enough, you need to tie both hands behind your back.
In all earlier titles, getting a good start was slightly more challenging.
How so? Besides licenses, this isn't true. I started GT1 with a Viper GTS. I didn't even need to touch the main events to get it. I won 86 spot races, got 86,000 cr, and went straight to Dodge.
GT2 introduced Cobra grinding to get the Viper GTS-R Team Oreca, then Speed 12 grinding to get everything else.
In GT3 I golded the licenses before buying a car.
In GT4 I started with 100,000 credits.
Like I said before, in GT, you cannot lose money. So the idea of GT being difficult doesn't make much sense. All you need to do is grind money and you can do more or less anything.
There are a number of bad, game ruining ideas that can change this, like making all the good cars prize cars, requiring you to win a certain race(s) before other races unlock, having to pay continuous car maintenance so that it's possible that you have a net loss of money even when you win every race you enter because you own cars that are too expensive for you. Etc. But IMO, the game is better without credits in the first place.
Now, if PD were to wake up and decide to give GT Mode to the GT Mode players and create a Sim Mode for the racers, fine, everyone wins. But this seems to be beyond them for some reason.
That's what makes grinding necessary.
If your only goal is to beat GT Mode, grinding for
money is probably not required. There's plenty for that.
GT5 needs griding because of the horrible XP system and because people want a lot of cars, which costs a lot of money.
a) you silver the B license (for the OFC-1)
b) if you do all the licenses up to I-A (for the Miata and the RAM truck)
c) if you take on the Stratos in the Festival Italia with an Autobianchi (meaning sinking a bootload of cash in it)
d) if you take on that ridiculous Bertone Miura in an Alfa-Romeo Giulia
e) sink gazillions of cr in over-tuning cars, so that your dimwitted B-Specks can win the cars you'll need for the few A-Spec races that the games actually provides.
I just did some special events and got a Viper ACR. That car took me through quite a few races. I very rarely buy a car for A-Spec, and I never use my online cars for A-Spec.
moral of the tale: PD just nailed "something" together as a sorry excuse of off-line play, relying that we will play online most of the time anyways. But that's not the case for all. If PD doesn't either patch the hell out of GT5
We can only hope.