No, Apple will still have the advantage of not being restricted like 3rd party apps when it comes to running background activities, access to hardware features they haven't published APIs for, and integration opportunities via private Apple only APIs amongst their various apps and platforms that 3rd party apps can't replicate since Apple literally doesn't make those knobs available to them.

Why can't my non-Apple laptop start a tethering session automatically with an iPhone when I open its lid? What good reason is there that a 3rd party tool can't generate an auto-reply to a notification from a chat app with my consent? Lots of user experience niceties that Apple keeps only for their 1st party apps to the detriment of us all.

Google does similar things on Android, but at least you can get most of these features through 3rd party stores like F-Droid.