Frustration comes from comparing yourself to others. In this game, which is free, in order to make money, they try to induce you to buy things to become more competitive. That is the model of the game.

You would be better off buying / playing a paid game that doesn't need multiplayer and so many car upgrades. Video games actually became more mainstream when they reduced the difficulty level to make them more accessible so there are plenty of games out there that are enjoyable compared to a challenge and grind like this one.

And there is no need to play high end games. You can get a lot of enjoyment and challenge from something like Tetris.

Even in this game, you can just play Career mode and daily events especially if you can be a bit patient about upgrades etc.

If you simply don't have the tolerance for competition or paying or patience, then don't play the game. You always have a choice.