Mac OS app - intel based to silicon

Have you tried the web version of the controller?

Look in the App Store.

There is no App in the macOS App Store.

Yes. The app is less intrusive. It means having a webpage open which I don’t necessarily want. The app was ideal as can minimise it and it not affect my work.

Sure there is, search for “phonos ultimate” in there. (Searching for Sonos doesn’t find it, because Apple).

Whilst that is a solution and appreciate that someone has spent the time to make and produce an app, it is still a paid app and this shouldn't be the case when spending a considerable amount of money on speakers...

As far as we know, Sonos has no intention of releasing an Apple Silicon version of the desktop controller. They intend to eventually retire the desktop controllers altogether. So, your options will become limited if you want to continue to control your system from the desktop. You should let Sonos know how you feel about that using official feedback channels. Posting here in the community will probably not get a response from Sonos.

As long as you aren't expecting someone to provide a free** app I agree with you.

** Free often includes some nasty data harvesting, scams and other unwanted stuff. Make sure it is really free and not selling your information for hidden profit.

FYI - The web app looks and feels like it is a standalone app - it doesn’t appear as a tab in browser. I was skeptical at first but the experience is much better than the old native app. The web app allows them to ship faster and build across devices a lot easier I’d guess. 

On my (not a Mac) I can have the web app as a tab or in it's own window.

I usually run it in the Brave browser, mostly so the taskbar icon is easy to pick out from the multiple ones for my usual browser. It shares tabs nicely with my security camera monitoring web page.