I started to get bored because it was so easy to get to the top of the career, easy to make money, easy to form relationships, etc.
So I changed my gaming style to a much larger rotation of sims. I think I have about 35 households in one load (and growing)
and all of them have been through various challenges or hardships. They don't level up as fast when I rotate through households.
Even then the relationships were still too easy and while I never thought I would mod my game I finally did and it's added a fun extra dimension of emotions and life details. I don't play it for how tough it is but now more for the plot that's developed between the various households.
Really I just had to work on making it more challenging... well...I think I mean more interesting tbh