I still do league racing and the odd daily but I don't race it much for the following reasons;
The races aren't races, they're time trials with rubber band opponents. The way they've adapted sophy is that it piggybacks off the rubber band AI, so while the racecraft is more lively, it still waits for you to pass before following closely. Sophy will fail unless the basic AI is overhauled, and given that sophy was cooked up in part because PD didn't think they needed to fix their own AI, I don't see them getting around that impasse.
My experience with upgrading cars is that it makes them handle worse than stock, meaning you just waste your credits.
The economy sucks, the goal of owning everything is terrible and there's no progression, it is a very bad game. If they wanted to, they could make challenges that rewarded you cars like the barker tourer which are cool but completely useless.
The roulette wheel is an absolute scourge, I don't want to be rewarded with waiting 30 seconds to win a crap prize. There's no anticipation, it is a chore.
Look at Rockstar Games, GTA online has been out for 10 years, they are constantly reinventing things, adding challenges, adding small prizes, offering big prizes for very difficult challenges - things that keep people playing the game. No way that happens if every prize was a spin of the roulette wheel.
The pieces are there for it to be a decent game even with the really bad AI, but noone in a position to influence the game cares about making a good racing game, they just want it to be a virtual marketplace where you buy credits so you can buy all the cars like a good consumer and make all the shareholders happier.
Really the biggest issue is that there's no progression after the first few hours. Even then that sucks and is filled with the laziest requirements like taking a photo of a car. There's no sense of career, There's no flagship races, truly outstanding that they achieved this total absence of progression while also hiding sport mode and tracks behind Level barriers at the same time.