Pros (ironically):
1. the app store manager is supposed to check the app for malware and viruses before publishing it, ironically all the apps full of Google ads, Google and Facebook trackers of any kind are welcome ...
2. make it very easy for the user to search, install and update the apps, if he can find what they are looking for through billions of game apps and very similar apps that are only published to send advertisements to the user or to collect his personal data.
Disadvantages:
1. you are tied to the whims of the app store manager
2. You have no control over the app publishing process: You cannot decide if you can publish your app or not, only the App Store Manager has the power to decide when and if it is convenient for him. I think only the user should have this right.
I'd prefer to install the native commercial native apps (for example, the home banking app) on my phone by downloading them from the developer's website, in a private area that I have to access with my credentials, where the app is GPG signed and I can check the integrity of the package. An auto-update feature is doable.
For open source apps, there is the F-Droid store where you can add your own repository (a bit technical and not for everyone, I admit : pre installing F-Droid on the new phones could help a lot, but I don't think Google will ever allow this).
Another viable option is PWA. In my opinion, there are very few apps that need the native features, for all the others, almost everything is now doable with PWA technology, and you do not have to bother sending updates to users or asking them to upgrade.
The monopolistic and commercial app stores, with the excuse of making life easier for users and in a supposedly "better security", are a "wonderful" way for Apple and Google to make billions on the work of independent developers and, in the case of Google, to collect and sell personal data about users and to sell ads of any kind in any way.