When Google initially launched the mobile streaming feature for YouTube, it was only limited to just youtubers with over 10,000 subscribers. Later on, YouTube dropped the requirement from 10,000 subscribers to just 1,000 subscribers.

Now, YouTube has silently removed all requirements and restrictions which means all YouTube users can now use the mobile streaming feature irrespective of the number of subscribers you have.

Although the feature is now made available for all, you must note that your channel needs to be verified and you must have no live stream restrictions in the last 90 days in order to start using the Go Live feature.

Also, the update is being released in batches, so if your account is verified and you still can't find the live streaming option then you have to wait until it gets to you.