Maybe note 9 is smoother than Nova, but only for the first 3 months. If you use longer period, you will start to experience lag. If use more than a year, it become bad to worse to be frank.

Too many duplicated apps, how to become smooth?
Google Store & Samsung Store
Bixby & Google Assistant
Google Keep & Samsung Note
Google Photo & Samsung Gallery
And the list goes on

That's too much really