As of now, Youtube doesn't forbid gambling streamers so your argument about being restrictive is somehow invalid. It is possible that the time will come for Youtube to do the same thing as twitch but not at this moment.
I remember reading in the past that youtube only allows gambling content where the gambling site is approved by them(similar to what was written on the twitch announcement that was posted on a thread here in the forum), so as far as I know, they do restrict certain gambling content that violates their community guideline. that being said I am not sure if they are more restrictive than twitch but as far as I know, they do restrict certain gambling content.