There's a huge amount of value in having an ecosystem of components that are designed to work together, and randomly choosing "oauth X" and "smtp Y" components and trying to string them together, vs using a battle-tested and supported stack, just invites a lot of hurt.
If you have a team of Java web app devs, having them build a web app in Rust or Go will be incredibly costly and inefficient. It seems very obvious to me, but I still get people that say "oh, it's not that hard - library X can do all of that other stuff"... but inevitably it can't. And the communities of people doing web app stuff in (Rust, Go, Scala, etc) just aren't big enough to provide the community support other frameworks provide.
Kudos to the author for their epiphany.