That would be nice in the future. Unfortunately, the modern Web is not even in the ballpark of being secure enough for something like that (and it’s trending worse, not better).
I’m in the US, and I can assure you the amount of effort that would go into breaking that system would be 1000+ fold.
Here’s the thing… your computer/phone, just to run programs, is sitting on somewhere around 40-50 million lines of code in the operating system. It’s got another 20-30 million for all the supporting user space libraries. People want to vote from any device, and operating systems have become walled gardens. Now we need to interact with browsers. That’s another 30 million lines. You know how many bugs I need to find to compromise a system? 1. It’s not necessarily a skill issue. It’s an attack surface issue.
And this is assuming the bug was an accident. There are much more insidious vulnerabilities out there (see the recent exploit found in xz). Along that same vein, there could be exploit generators in the compilers (that’s 15 million lines) that build all these systems.
We won’t have online voting until we fundamentally change how we compute. I don’t see that happening any time in the near future. None of these corporations are going to be breaking down their walls anytime soon.