I believe it was once said, "With great annotations comes great responsibility."
YouTube's annotations are a powerful tool for engaging viewers, but they can quickly spiral out of control and become more of a distraction than an interaction. Thankfully, you have ways to combat incessant speech bubbles, from eradicating them one by one to erasing their existence altogether.
First, the soft approach. You can disable an individual annotation simply by hovering over it and clicking the resulting X button.
The intermediate approach is to turn off all annotations for the video currently playing. Click the gear icon in the menu bar along the bottom edge of the video player. A settings panel will pop up with a toggle switch to turn off annotations. Note: this switch will also turn off YouTube's new interactive cards.
The third approach is the nuclear option. If you don't want to see annotations (or cards) for any video whatsoever, you can disable all interactive elements by heading to settings, clicking on Playback from the Account Settings panel on the left, and then unchecking the box for "Show annotations, channel promotions and interactive cards on videos."
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