The power of open source network effects are gone

It was a legitimate reason to pick a language or framework because of the libraries that were built for it. LLM coding agents completely upend this. You can now do completely automated mechanical ports from one language or framework to another. Soon you will be able to do automated idiomatic ports. This capability of AI coding agents to port has already been demonstrated by Bun's port from Zig to Rust. Translations like this are LLMs biggest strength.

It's now more important than ever to understand the properties of the technologies you choose when building software. There are technologies that people are still using that we know to be worse because they are the default and the reasons for choosing those technologies do not exist anymore.

Ecosystems still matter in some places

• The web. All the old websites that are sitting around aren't going to be ported to something other than html, css, and js. It's also a miracle that an open platform like the web is supported across all major computing platforms. New websites might move to web assembly though.
• Vendor lock in. Do you absolutely need S3 Express One Zone? You're stuck on AWS.
• The physical world. Unfortunately you can't just port all your tooling for free to work on some other physical device.