Because windows now literally has all the stuff Linux has plus a lot more.
The only reason for a well paid developer to prefer linux over windows for a desktop OS is that you don't need any of the extra stuff (a decent desktop experience, hardware support and a commercial end user software eco system) or that you have some fundamental objections concerning Microsoft's business practices. These are good reasons, but experience shows that most people don't care enough about things like privacy to give up convenience or shiny things.
Apple may be in for a tough awakening. They profited enormously from providing the desktop OS that a very large fraction of the technical elite has been using for a long time. MacOS still is still smoother than windows in some regards, but the writing is on the wall: linux completely dominates the server but is as hopeless as ever as a general purpose desktop OS, but windows no longer sucks for software development. It used to be that macs had the unique selling point of offering a nice desktop experience on good hardware coupled with something close enough to linux that you could use it for a very wide range of software development tasks. But new hardware is developer hostile and macOS drifts further and further away from linux (ever more lock-down that directly breaks developer workflows and tooling and ever more diverging user land with a mix of ancient GNU and irrelevant BSD tooling). By contrast windows now includes an ultra-high-fidelity linux layer with excellent tooling and integration to "core" windows and Microsoft also owns the world's most popular editor and code hosting solution.
I'm amazed how well Microsoft has managed to find back to its embrace, extend, extinguish roots. It is both a technical and a strategic marvel.