Your Mac takes a while to be usable after you log in, and four things you did not ask for have opened themselves. The setting is in System Settings, under General → Login Items & Extensions.

There are two lists in there. They are not the same thing, and switching off the wrong one breaks things.

To go straight to the pane:

open "x-apple.systempreferences:com.apple.LoginItems-Settings.extension"

The first list: Open at Login

This is the honest one. Everything here is an application that opens when you log in, and every item is safe to remove — the worst outcome is that you open the app yourself next time.

Select an item and use the − button. Some apps put themselves back the next time you launch them, which is dealt with below.

The second list: Allow in the Background

This is the one people get wrong. It is not a list of apps that open at login. It is a list of background items — helpers, updaters, sync agents, drivers — that apps have installed and that run whether or not the app is open.

It is grouped by developer, which is why one line can say "Google" and cover three separate pieces of software. And the names are often unhelpful, because they are the identifiers the developer chose rather than anything designed to be read.

Some of these genuinely should be switched off. Many should not:

• Backup and sync agents — Backblaze, Dropbox, Google Drive, OneDrive. Switch these off and the thing stops backing up or syncing. Silently.
• Updaters — Microsoft AutoUpdate, Adobe, Google. Switching these off means the software stops receiving updates, including security ones.
• Drivers and system extensions — audio interfaces, tablets, VPNs, printers. These are usually the reason the hardware works.
• Things you removed an app for months ago. These are the real finds. An entry for software you no longer have is dead weight and safe to switch off.

The useful rule: if you cannot tell what an entry is, leave it alone. The time it saves at login is a second or two, and the failure mode is a backup that quietly stopped running in March.

The app keeps coming back

Two different causes:

The app has its own setting. Most apps that open at login offer a "launch at startup" preference of their own, and that setting is the one that wins — remove it in System Settings, open the app once, and it puts itself back. Turn it off inside the app's own settings instead. That is usually in the app's Preferences under General.

It is a background item, not a login item. If removing it from the first list does nothing at all, it was never in that list — look for it in Allow in the Background instead.

Where the old LaunchAgents went

If you have used a Mac for a long time, you will have read advice about ~/Library/LaunchAgents and /Library/LaunchAgents. Those folders still exist and still work, but since Ventura, anything in them also appears in the Allow in the Background list, which is a much better way to see them.

The one place still worth a look is ~/Library/LaunchAgents in the Finder — use Go → Go to Folder and paste the path. Items left behind by apps you deleted are common there, and they appear in the list above as entries for developers whose software you no longer own.

Making the login faster, generally

Login items are usually not the main cost. Two other things matter more:

• Reopen windows when logging back in. The checkbox on the shutdown and restart dialogs. If that is ticked, your Mac is not just starting login items, it is restoring every app and document you had open.
• What is actually running. Activity Monitor, sorted by CPU, in the first minute after login, will show you the real answer rather than the guessed one. It is in /System/Applications/Utilities, or open -b com.apple.ActivityMonitor.