Success as Content Creator/Influencer - Question on Substack/YouTube/Podcast for Alex/Rahul/Michael Lin

So I have just restarted a new Substack and have a good amount of Subscribers before officially releasing everything (I'm migrating people off of other email lists I have and other sales list for prior products I've created). What is a good metric in terms of starting number for Substack and if we adopt this content on YouTube/podcast, what is a good aim or number?

So for example if my list is 2K on Substack with a 50-90% open rate, what's a good number to target for the other platforms, YouTube and Podcasts? // And yup, I'm very picky about content so I keep my content a high bar so that it always has a high click-thru rate, so people ALMOST NEVER unsubscribe and feel spammed, I can count that on my hand after maintaining several email lists over the last 10+ years for different organizations/OSS projects etc. I wasn't obsessed with growth, but more like a loyal audience that stuck by me and was a part of a larger organization/movement/customer base I could go to consistently.

What's a good initial target for YouTube subscribers and podcasts?

I have friends that are content creators that have this as their single channel and have at least 20K subscribers (YouTube), or Instagram (some are who are non-technical and don't work in tech, that work as models in Hollywood, "tech corporate girlies", others who worked on video/Instagram at Facebook and are authors, and have at least 1M subscribers). I sometimes find this a little bit out of reach, or at least for a lot of what I find, people subscribing mainly for entertainment or to look at a pretty girl, rather than to learn (which is the majority of my content). I know friends who have earned six figure book/film deals from their content on TikTok (Harvard Law School alumni) and I'm wondering how I can have a realistic target without getting too intimidated or feeling like a goal seems like it is hard to attain that 'overnight' success that I've seen so many people tell me they were able to garner in the Clubhouse/TikTok boom that have attained this level what feels like it's overnight, and I feel stuck at such a low number by comparison, even though my engagement rate is higher and my content is completely different (more in-depth than me showing lifestyle content of "what I ate at the Google cafeteria today with a developer meme" and more like "here's how you can code x y z and use x y z framework to make x y z app" or "x y z investing/daytrading/productivity hack."