Yes. This. 100%
Even Freeplay has more stairs than Sims 4.
A game that I've paid for, has me missing a game I played for free, simply becuase of its lack of some obvious features.
Whilst I enjoy a lot of the building features and I have to say, building was a big push to get me to actually go for it and finally buy this game, sometimes I get frustrated that I'm missing some things that I got in a game like Freeplay, frustrating as that was to build in. Freeplay has the regular straight stairs of course, as well as a fireman's pole (complete with ladder so you can climb up it as well), elevators, switchback staircases and spiral stairs. I know they're different teams, but it frustrates me that in some ways, I have content in a freemium version of a game that is lacking in a paid version of a game.
Also, if I can create diagonally-placed houses, then I need to be able to place stairs diagonally too. As for the stairs, switchback and spiral stairs are essential for small, compact builds. The straight ones take up too much space in some houses. We need options, just like how we have different wall heights, which are great.
Finally, I would love some sliding down the bannister animations. Those are awesome!