I would like to see new life states unique to Sims 4 so that it has something no previous sims game has. It avoids comparison as well of previous games doing it better, which sadly often is the case like with plant sims especially.
I would like to see androids as a new life state, as a bridge between sim bot and sim.
They could wear human clothes and pass for human depending on what skin and eye colours you pick. They do not age but require maintenance, if not maintained they shut down and become an object that requires a lot more tinkering to reactivate. Like a new power source crafted from rare minerals.
Instead of experience granting them new abilities, they require costly upgrades that can put a lot of unique metals and other relevant collectibles to good use. Such upgrades can make them water proof, require less maintenance, unlock specific emotions since they start out not having any which can also come with unlocking extra needs. Initially they don't build up relationship with other sims either but other sims do with them. Requires a social upgrade.
Some skills they could have maxed out from the start, but all other skills they can't learn until they get an upgrade to unlock it. Like they can't learn anything creative. Those are some of the toughest upgrades to make for them, while skills such as logic they could upgrade more easily so they can learn them. Athletic would be a skill they start with having maxed out.
An android sim could be created, in a longer process than creating a simbot. In CAS they could be fully finished androids, but a created android could have a prototype stage in which they are active and look like a metal skeleton. Depending on the skill of who is making them, there could be a chance they run amok and destroy stuff when first activated, but they could already prove helpful in the prototype stage, helping complete themselves but they are also more vulnerable when not yet finished.
Like a finished android can walk in rain but it drains their maintenance need, a prototype android would shut down if walking in the rain. Unfinished they also lack the athletic skill completely, and if someone fights them they will break if losing the fight, shutting down.