There is the Profiles way of doing themes, it’s much better than the Shortcuts one:
Personally don’t care for theming, I got over it on android back in 2015 or so when I got over using Launchers and all that stuff.
I’ve been pretty happy on iOS, probably due to the fact that j don’t care much for all this customization anymore, lol.
I remember dabbling with custom ROMs, before “OneClick ROOT” was even a thing and doing all sorts of modifications including overclocking on the Galaxy S2, nearly bricking my Xperia X10 back in 2010 when trying root methods and trying out all sorts of CyanogenMod stuff on my Galaxy S3, good times.
I have my Huawei P40 Pro to satisfy any sort of desire to go bananas on customization but I setup it’s home screen similarly to my iPhone’s homescreen which is to have a News Widget, Music Widget, weather Widget and folders of my most used apps.
It’s been interesting to watch the TikTok kids go bananas with the iPhone modifications though, iOS getting more Android features is a good thing for both OSs I think, it helps brings more creativity around that stuff.