What I don't get about all the "if you plan it out first, it gets better" approach is, how did they work before?!

For anything bigger than small size features, I always think about what I do and why I do things. Sometimes in my head, sometimes on paper, a Confluence page or a white board.

I don't really get it. 80 % of software engineering is to figure out what you need and how to achieve this. You check with the stake holders, write down the idea of what you want to do and WHY you want to do it. You do some research.

Last 20 % of the process is coding.

This was always the process. You don't need AI for proper planning and defining your goals.

That might be true for large dev teams with an established culture. But a lot of development is happening in different settings - solo projects, small teams, weekend side-projects, personal tools crafting, quick POC coding, etc. Not all software is a complex product that needs to be sold and maintained. One thing that I always loved about being a developer is that you can create any custom piece of software you need for yourself – even if it's for a single-time task - and don't care about releasing/supporting corner cases/other users.

In almost all these cases, development process is a mix of coding & discovering, updating the mental model of the code on the go. It almost never starts with docs, spec or tests. Some projects are good for TDD, but some don't even need it.

And even for these use-cases, using AI coding agents changes the game here. Now it does really matter to first describe the idea, put it into spec, and verbalize everything in your head that you think will matter for the project.

Nowadays, the hottest programming language is English, indeed.

I think I usually mix the coding and the designing more. Start coding something, then keep shaping and improving it for a while until it's good.

And of course for most things, there's a pretty obvious way it's probably going to work, no need to spend much time on that.