Surprisingly, a lot of people don't know how to hold a camera. This can help (with video):

https://photographylife.com/how-to-hold-a-camera

Or you could just buy a Canon with image stabilization.

I routinely hold my 100-400 at 400 free hand without any image blur.

Much easier...

Good technique always improves pictures, image stabilisation only helps in some situations. In fact, image stabilisation works better when you use good technique to start with.

Years ago I took a course in pro photography and one of the first lessons was how to hold a camera to get the best picture. When I saw how it is done these days I was blown away but most of the people taking the pics don't care or need a quality photo for social media. With improvements in hardware we do get better pics using poor technics but good practices still win out in the end.