1) The one-time, one-day waiting period only applies if you go through the advanced flow to allow installing unregistered apps. You can still install registered apps (ie. apps made by developers who have verified their identity) even if they're distributed outside the Play Store.
2) You can use ADB to immediately install unregistered apps. ADB installs are not subject to the waiting period.
3) And how can we keep on using F-Droid and other app stores?
4) How can we install apps made by devs who won't do the verification dance with Google?
I want to use the apps that don't hellbent on your Google right away. This is MY phone. I paid my money. I don't want Google to dictate what I should do.
1) Fuck
2) Google
So let's say I'm F-Droid, an organization making a direct competitor to the Google Play Store and openly pointing out how much scammy shit is available in that store. My options are 1) submit my identity to Google (my competitor) so they can identify me and choose to revoke that verification at any point, or 2) I can tell all my users that they must go through these scary dialogs AND wait 1 day before they can use my competing product? That's cool, glad we've got the options laid out in front of us.
I forgot 3) instruct my users how to use ADB from another computer to install my competing app. Awesome.