The button is everywhere now, and it is hard to argue with. You land on a new app, you see Sign in with Google or Sign in with Apple, and you tap it instead of inventing another password you will forget by Thursday. Nothing about that instinct is wrong, and in most cases it is the safer choice. What almost nobody does is stop and read the small screen that appears next, the one that lists what the app is asking for. That screen is the entire deal being made, and it takes about four seconds to actually read. The reason it goes unread is that it looks like a formality rather than a contract.
Here is the mechanic underneath it. You are not giving the app your Google password, and that is the genuinely good part of this system. Instead, Google confirms who you are and hands the app a token, which is a limited pass that says this person is verified. The app never sees your password, never stores it, and cannot lose it in a breach. That alone puts this ahead of creating a fresh account with a password you reuse somewhere else. Password reuse is still the way most ordinary accounts get taken over, and this button removes that risk entirely.
The part worth slowing down for is the scope, which is the list of permissions the app requests. Basic sign in usually asks for your name, your email address, and your profile photo, which is reasonable and roughly what you would type into a signup form anyway. Some apps ask for much more, and they ask in the same friendly tone. Access to your contacts, your calendar, your Drive files, or the ability to send mail as you are all things an app can request on that screen. Once you approve it, that access continues in the background whether you open the app again or not. The request is a single tap, and so is the approval, which is why the two blur together. Most apps also keep that access after you delete the app from your phone, since removing the app does not revoke the grant.
The second thing people miss is what happens to everything downstream if the Google account itself has a problem. If you lose access, whether through a forgotten recovery method, a lockout, or an account suspension, you have not lost one login. You have lost the front door to every service you attached to it. Recovering a single app account is usually a support ticket. Recovering the account that unlocks thirty others is a different situation, and the apps themselves cannot help you, because they never had a password to reset. This is the tradeoff for the convenience, and it is worth knowing before it matters rather than during.
There are two habits that fix most of this, and neither takes long. The first is to actually read the permission screen and back out if the request does not match what the app does. A photo editor asking for your photo library is expected, and a photo editor asking to read your email is not. The second is to review what you have already approved, since almost everyone has years of forgotten grants sitting there. Google keeps this list under your account security settings, and Apple keeps a similar one. Ten minutes of scrolling and revoking usually removes access for a dozen services you stopped using long ago. It is also worth keeping a separate password on the two or three accounts you could not afford to lose, such as your bank and your primary email.
The other piece is protecting the account that everything hangs on. If one login controls the rest, it deserves better protection than the rest. That means two factor authentication turned on, ideally with an app or a physical key rather than text messages, since text codes can be intercepted. It also means recovery options that are current, because an old phone number on file is how people get locked out permanently. Print your backup codes and keep them somewhere physical if that is what it takes. The effort is small and it only has to happen once.
None of this is a reason to stop using the button. For most people, most of the time, signing in with Google or Apple is the more secure path, and the alternative is usually a weak password typed into a site that will eventually be breached. The point is that convenience this smooth tends to hide the terms, and the terms are not complicated once you look. Read the scope, prune the old grants, and lock down the one account that unlocks everything else. Do that and you keep the convenience without the quiet exposure. That is a fair trade, and it takes one evening.
