Serviced apartments typically aren't "permanent", though, they're rented by the night like a hotel rather than on a longer-term basis, so they cost a lot more, to compensate for the high vacancy rate.
There are also permanent serviced apartments. An example that comes to my mind in the UK are the apartments in the Shard, which are serviced by the Shangri La but I believe were sold, not rented.
There is also Ascott in Asia, which are typically collected and comanaged with 5 star hotels. I had a friend who lived in something like this full time when I was living in Beijing.