So I'm not entirely sure what DE your using, assuming it's Budgie or Gnome, you can theme it to look more like Big Sur. I'm not sure how you'd get to an iOS look and feel given that's built on a mobile paradigm and Solus is focused on desktop computing.
For Big Sur
- In Budgie - Set the panel to dock mode in Budgie Desktop Settings
- In Gnome - you'll need Tweaks and Dash to Dock (if it's been updated for Gnome 40)
- Download the WhiteSur GTK theme and install that
- Download the WhiteSur or mkOS-Big Sur icon pack and install that
- Download the Big Sur cursors and install those
If you're looking for something truly mobile inspired, you may be better suited looking at something like EndlessOS or JingOS. I think JingOS is only supporting x86 devices currently, not sure what your machine is. Endless does have an x86-64 iso available.