I think it would be better to make it more challenging but not SO challenging it's super hard it just needs to be made harder to do things especially to earn money and now with the internet and people being able to sell things on it anything they sell at home even their crops if they want to make money off growing fruit and veg then i think there should be a limit of say... 2,000 simoleons then if they want to earn more they have to register as a Seller (where we can choose what we're selling), but like all sellers and businesses you get charged for running a home business of any kind cos when you start making lots of money from other people for it then it is technically a Business, and so they should get charged some sort of fee per day depending on what they're selling. So far you've just grew Fruit, Veg and Flowers and then you just click "Sell..." lol and they can earn a lot in 1 sim day.
The price of what things sell for needs to be reduced too especially Excellent Quality especially plants like Snapdragons those can go for like 2,000 simoleons per bunch lol that's insane and too high you'll become rich in no time at all... per bunch it starts to quickly add up and your already rich, and then i think how long they take to grow should take longer or balance the fee per day with how long most the fruit, veg and flowers take to grow, but of course if they don't sell anything in a sim day then they don't get charged the fee. It just has to be made harder so they don't earn too much too fast.
Being promoted has always happened way too quickly too where they start earning several thousand per day but it needs to be harder to gain a promotion and then maybe it gets harder as you go up and what you need to do to earn that promotion like it realistically should, i think if it's harder for them to earn money then it makes it more of challenge to pay for Bills and stuff too and it's just way too easy even for 1 sim even at the start of a career they may not earn enough from their wage but then they can just sell Paintings which can sell for a few hundred simoleons at the beginning of the Creativity Skill and then it takes too little time to paint it i think it should take longer if not then how much they earn from them has to come down.
In general other things like making friends, building relationships, earning Skills it's always been too easy as well but i think if it's made harder in a balanced way then everyone will be okay with it and it will then make it more fun for everyone, it doesn't have to be too difficult cos for anyone when it feels too difficult your not gonna have fun anymore.