It is infinitely easier to talk than act so this critique is in deference to the entrepreneurs in the arena. With that said, I think Substack should’ve done 2 things differently 

1 - Tailor the product to power users, specifically publications (file under things that don’t scale) 

2 - Embrace advertising

One thing their financials showed is that whatever strategy they pursue, they should’ve been more stringent with spending

At the going rate they will need to execute their pants off to steady the ship even with deep cuts to head count