Twitch's metrics haven't progressed greatly and are sorely lacking updates.

The following should be available as a gold standard:

• Live Views (*currently available)
• VOD views of archives (doesn't seem to exist in data export; or is rolled up into somewhere? What happens when the VOD archive gets deleted?)
• VOD Views of created clips (*currently available)
• Average View Duration (avg. mins watched per unique viewer)
• Data Export of Views by Platforms (Views by Web, Console, iOS, etc.)

Nice-to-Haves:

• Followers Gained / Followers Lost
• Live Views by Non-Followers
• Live Views by Followers (and possibly even Subscribers)
• Impressions (Auto-Play directory, Auto-Play frontpage where no sound or clickthrough)
• Impressions CTR (how many people are clicking you when seen in a directory)
• Ad Dropoff/Exits (Unique Viewers or similar who exit during an ad-server-provided ad)

And Don't Forget:

• Trending: Daily What Categories Do My Viewers Watch (not weekly). The example is, if a massive Early Access game trends (e.g. Among Us). Within 24 hours we should see if our viewers have been watching a major trend. Waiting 7 days for minimal data is not that helpful with how fast things move.