If what you said was true there wouldn’t be any companies outside of like the caymans islands. Taxation is not the only thing a company look at when choosing where to go. Sure obviously you can’t tax at 100%, but we are currently way lower than we used a few decades ago, so we totally can raise it (actually just go back to what it was even just 10 years ago).

True, there are many other factors. But companies can simply have the legal hq in caymans and everything else in other countries. And a company could always choose to leave a given country if it decide that it is no more convenient for whatever reasons, for example Stellantis as far as I know moved the legal hq in Netherlands and keep paying the taxes - at lease some - in Italy, but nothing force them to never leave Italy.
But I am not really sure that we can raise the taxes to the level they were 10 years ago.

As for the retirement age of 60, you say it is impossible yet it was the retirement age in France until like 15 years ago. Since then we dramatically reduced the taxation on companies and capital gains, and slightly increased the age of retirement. That is to say it is absolutely possible and does not demand big systemic changes, only some adjustments on a few variables.

I say that it is impossible now, not that were always impossible. Also in Italy we had our share of people who retired early (to the absurd limit that for some years people 30 years old were able to retire, back in the 1970's).

You say that if we raise the taxes to the companies we will be able to retire at 60, but with which life expectancy ? For some times it could work, but then as the life expectancy raise and the birth rate lower, you will have an always increasing number of people with an longer life expectancy (so you need to pay them more money for more time). And we both agree that the tax on a company could increase only to a certain point, so where to get the money in a situation where you have a lowering number of workers and you are walking on a razor blade with the companies ?

Also the retirement age until 6 months ago was 62, and projections for the next decades showed the system would be making benefits for a few years, then deficit, then back to benefits later in the century, while keeping everything (tax level, retirement age) the same.

That was the same error done in Italy in the 1970's and 1980's, where they thought that the economy will grow forever, and failed as the conditions changed. I mean, it could have worked if the economy had continued to grow and if the birth rate had been at least stable.
What you think now it not what will happen 20 years from now. You need a system that is more resilient.

The choice was to reduce taxes on companies and capital gains, and raise retirement age, which would end up costing more in like 30 years from now than if we kept the same age (not even talking about not reducing taxation on that point)

Or we can raise the taxes on companies and capital gains and the retirement age however unpopular these actions are.