You will notice that when you link your channel to TubeBuddy, it takes you through Google's "OAuth" process which requires you to grant access to us. And not just regular access but "see, edit, delete YouTube videos, ratings and captions". Which we understand sounds scary. However, it's the industry standard for 3rd party software products and there is no way for us to build amazing tools without also having access to your channel.
Please be aware that we don't perform ANY actions without you specifically asking us to. For example, we never update a video unless you specifically say "TubeBuddy, please update video X". And we don't have any features at all that delete videos so you can't delete a video through TubeBuddy even if you wanted to.
If you are still concerned about granting access to TubeBuddy - feel free to do research about our company or simply choose not to use it. Plenty of successful channels don't use TubeBuddy. But the ones that do, have an advantage.