As of right now, Android does not have this functionality included. Dev previews suggested for this to launch for Android 14 but this was not the case. Android 15 might get it, but that is just a guess.
However, depending on your device manufacturer, there might be options such as Dual App, Parallel Apps, etc. by Samsung, Vivo, OnePlus, etc...
As Frank suggested, another Youtube client such as NewPipe might be the solution for you, if adding a second account in the youtube app is not a acceptable solution for you.
Just as a warning: Google is cracking down on third party ad blockers for YTcracking down on third party ad blockers for YT and / or might go after 3rd party clients. Some say that using NewPipe can be riskty to use and result in an account ban, but that is something you need to decide