Experimental Modern UI enabled by default without user consent - unacceptable

**Experimental Modern UI should not be enabled by default in Stable**

We opened VS Code after a routine update and suddenly found that the entire interface had been changed to a new “modern” design, with floating panels, rounded corners, and other significant visual changes that we never asked for or chose to enable.

This is unacceptable. **You are effectively vandalizing developers' workspaces without their consent.** Our editors are professional work environments that we use every day. They are not a playground for silently deploying experimental redesigns.

The setting is explicitly labeled **Experimental**. An experimental redesign should be opt-in. It should not suddenly become the default for Stable users and leave them wasting time figuring out what happened and hunting through settings just to restore the workspace they had yesterday.

More broadly, the frequency of disruptive changes arriving through VS Code's rapid release cycle is becoming exhausting. Developers build workflows and muscle memory around their editors. We should be able to install updates for security fixes, bug fixes, and genuine improvements without wondering what part of our working environment is going to be unexpectedly changed next.

We should not have to troubleshoot our editor after an update simply to undo changes we never authorized in the first place.

Please:

* Keep experimental UI redesigns opt-in on Stable.
* Stop silently changing established workspaces through routine updates.
* If a major default must change, clearly notify users and provide an obvious one-click option to retain the existing interface.
* Treat UI stability as an important part of backward compatibility.

VS Code is a professional tool. **Please stop treating developers' workspaces as something that can be redesigned underneath them without their consent.**