How do today's Youtuber record their videos?

Do you do that on Twitch or Youtube?
So record a game and record a good one on youtube.
Or on Twitch gamble record and then upload?

For recording mostly OBS Studio is used. This is available for Windows, Mac and Linux and can be downloaded here: https://obsproject.com/de/download If you have an appropriate graphics card, you can also enable hardware acceleration in OBS Studio, then the graphics card takes over the rendering. A Youtube upload function is also integrated.

That means no matter if youtube or twitch

You can also export the recordings as MP4 video and then upload them to other platforms. You are not bound to anything.

So almost no matter where you record.

ve twitch you may have been watching that makes the whole funnier?

But then you stream, and you can record the stream.