I do agree if you are looking for challenge game and always looking to beat it ... this game might not suit you without mods or self restraint or self restriction.
The thing is this game allows you to play out stories both of poverty or riches pretty easy. It's up to you as the simmer to drive that. So instead of doing all the achievement and fast money making things ... slow down.
Take your sims out with a group.. and pay for the meals. Buy good gifts for others and give them. Give your sims hobbies that they won't make money off of. Play an instrument, craft (and keep) some artwork. Get a crystal/metal or some other collection going. Send them out to do yoga or for a jog, send them out to have bar fights. Take the vacation days that are there for your sim to use. Stop hoarding the money or time like the one with the most wins. There is no winning in this type of game.
Try out giving some bad lot traits or character traits to your sims... heck bring the children up so they aren't perfect and not everyone will love them on first meeting. Avoid giving them traits that makes everything even easier. Go to festivals, try to learn to use chopsticks. Go swim at the pool (or build your own and have a party..). Use the central heat and air. Give to charity.... heck you can even burn your money.
When I first started playing the Sims 4.. I wanted to make money on my sims and make sure they succeeded. It was the only way I knew to play because of prior iterations and the habits I'd developed. I've lightened up a lot on that. I think I was more goal or challenge driven in prior games and the loosening up of driving needs and the ability to make money is there if I want it. I am at a point though where I don't chose the easy known path anymore. It was fun figuring out those paths though don't get me wrong.
Many of us don't want a pure challenge game. I want a game where my sims can live out their lives as I'd chose for them too do without work or money issues hanging over their head. If they do add more challenges in this game I hope they keep in mind us simmers that enjoy it as it's shaping up and don't force it on us.