This news from Heroku does not come as any surprise to the people that were there (as I was). Lots of moving parts and second guessing (that I won't share), but one thing I will say is: Incentives matter.
The seeds of this outcome were planted years ago when sales comp plans changed. When a sales rep can hit their target by simply converting the way an existing customer gets billed, none of them look for new business. Don't need new leads. Don't need to win competitive deals. But finding new customers and losing opportunities are the only things that signal/drive innovation. But from a budgeting perspective, why increase investment in a product that already hits/exceeds their sales targets?
Over time sales targets get met, but the product doesn't advance. By the time all existing customers that can convert have converted, the product is no longer competitive. Like bankruptcy, it comes gradually, then suddenly.
Most of my career, I've worked for startups and small/medium sized businesses, mostly using Ruby On Rails or Node based stuff for language/frameworks.
In every single company I've worked for in the past 15-20 years in this capacity the biggest focus was to exit heroku as quickly as possible. The reason: Price. You don't get to charge a premium for tooling, especially not when open source tooling exists that lets you use cloud providers without paying "the Heroku Tax".) Is Heroku still using AWS/any cloud provider? They should have rolled their own infrastructure decades ago. Alas, they got bought by a shit show of a company.
(Note: I stopped working in 2023 due to health, and much of my early career was ASP/PHP/.NET)