It's not my obsession, it's just how games are made. Since the beginning of video game design, there is a beginning and an end to the game.
That is not how GT7 was designed and not the way all games are especially those that follow a GaaS model like GTAV, RDR2, etc. It's all about player engagement and to get people to keep coming back long after the menus are completed, licenses, etc. .....keeping the game alive and ongoing. There is no "end" in GT7 like there would be in a story-based game like The Last of Us for example.
You're right, not all cars are needed to complete the menus. etc. (in fact just a fraction of what are available), but for folks like me, I enjoy exploring all of the various makes and models, experiencing their in-game characteristics, customizing and tuning them to work for me. Yeah, some are not as pleasurable to drive than others but then again, I have taken that as a challenge in some cases to try and become more proficient with them and/or find a tune that works.
Kaz has been very vocal about how a big part of this game is about collecting cars. He's also mentioned about how they don't want single events / races to be what people focus on for their "grind". Unfortunately, they haven't made too much headway in that sense and the root cause is the in-game economy.
As far as I've seen, most folks aren't asking for an easier go of it but rather payouts and an economy that make more sense. Fore example, one that doesn't lead people to grinding 1 or 2 races over and over again for the most gain. ....again, something Kaz says he wants to avoid.
As I mentioned earlier, payouts that made more sense in how they are calculated for the existing races would most definitely contribute to more player engagement IMO as it would provide much more variety and encourage folks to replay events, spend more time with other tracks, in other cars, etc. This would extend also into the Custom Races where folks already create their own experiences sometimes trying to replicate real life series. I know if they had a more consistent and linear payout model based on difficulty settings, PP, length of race and so on, I would spend a heck of a lot more time in Custom than I do now.
PD took a big step forward IMO with the big update as Custom races actually paid well (many of mine were well over 200k). Still there was a sharp drop off creating a point of diminishing returns after a certain length of the race but it was still better than it was. Unfortunately, they took a step back with the last update or "fix" they made to the game. Payouts decreased in Custom although they are still higher than they were before the big update. ....although I found a way around that "fix" to get more money.
Look, GT7 has no end. ....or at least it was never intended to. PD wants the game to be replayable. They want people to collect cars. They want people to keep signing on. It's all about player engagement, new tracks, new events, new cars to spend credits on, racing online and people creating their own experiences. They want consumers to keep
racing whether that's online or solo.