Apple just (partially) fixed the Calculator!

I never said and fully agree that the calculator on windows is insanely good in terms of accessibility and just convenience. Windows has shortcuts everywhere for everything or almost, it's obvious it's the perfect good example of a keyboard first os. But it's the sighted users fault who never learn the shortcuts so mouse is seen as de facto nowadays. Anyways.

But this bug is extremely irritating still. With the item chooser I can go quickly to any of the functions/buttons but I have to click on it, find the input area, click on it and then press = to get the actual result.

The calculator has very limited shortcuts compared to the calculator microsoft have on windows where every function or almost has a dedicated shortcut and hence it's very convenient for us blind to use it plus real screen reader support.
The bug which has now a very slight workaround is that for whatever reason since Ventura (first mac owned) whenever you would go out of the input area to click on sin, cos, sqrt... with vo arrows or the trackpad or tab/shift-tab it becomes impossible to type anything with the keyboard, digits, =, etc... Cursor tracking would fix part of this but it was too convoluted even with that. The search function with either command keys was giving very random result to to get quickly on a function, and anyway the bug mentioned above would occur anyway.
On Sequoia the Calculator now has gotten slightly better. It's a shame that nobody on applevis and other blind community never seems to mention that. Okay, I'm a developer too, using python or similar is no problem for me in the terminal or bash itself. But even blind users like guis.
@Applevis community if you know a decent easy to use and accessible (gui) calculator on macos for voiceover users please don't hesitate to mention it here. Desmos calculator is nice on windows where I don't need it but its interface is quite horrible on mac with safari and voiceover as VO is so... difficult with web.

Correction, the fix mentioned here also apply to 15.1.1, so all subsequent versions.

If you're talking about vo cmd fn 4, it doesn't work in this exact case hence vo-space (only). I've read about rpm mode, but my understanding was that it's something weird graphical, and at least in the standard and scientific there are very limited shortcut compared to windows for functions like sin, cos, tan... I might re read this document for the 10th time, and if I was wrong all that time, than congrat and thank you apple! Again, I'm 101% willing to learn new ways of doing things on an os.

Nope.
Literally 4-5 functions have shortcuts in the scientific mode, and everything else is said click x button in their doc. There is no useful shortcuts and as far as I know, we have to manually move with vo+arrows or the trackpad to the functions, which is painfully slow and trigger the above mentioned bug.
https://support.apple.com/en-ca/guide/calculator/calce87b2f66/11.0/mac/15.0
RPN mode as far as I know has the same problem. I;m not saying that microsoft calculator on windows with the shortcuts is the standard, but the lack of those + this bug with voiceover makes it very hard to use it, at least it's a bit better now.
Compared apple shortcut list to that of windows in the calculator app.
https://support.microsoft.com/en-us/windows/keyboard-shortcuts-in-apps-139014e7-177b-d1f3-eb2e-7298b2599a34
That;s why I say mac accessibility especially with its point and click interface can be questionable sometime, but again it's just two philosophies. I know I can use python to do all the stuff I need and more, or hopefully one day be able to code my own gui app, but the fact that their native calculator has been broken for probably years with voiceover and it's only this year with my feedback and maybe others that they dared include official real voiceover support for it... Because before it was a the system tts impossible to stop when saying 10+ digits periodic numbers for example.
Even if I could have hotspots for most of my commonly used functions I'd have to press 2 keystrokes for one purpose, first go to it and then press vo-space, and it's even worst for the inverse functions. Using command key as search was already broken and giving very weird results in calculator on Sonoma, and now it's completely broken for most things like you can't do cmd-d in textedit or similar app when going to delete button, in the four grouping behaviours.