The EU system is generally that you can't just "fire" people, you have to have a reason: either documented underperformance or misconduct. You can make redundancies by eliminating positions, but again this is subject to consultation and fairness rules.

If they did this company would be much,, much slower at hiring people and wouldn't bring people on till they knew they could always pay them. It would slow down company growth a huge amount. I doubt this will ever be a thing at least in the US.

Well making it illegal is less humane to business owners and goes against the concept of property rights. Who owns your business and sets policy, you or the government?

Tenure might make business sense because it would give employees a great incentive to not leave for positions at other companies.