[logicallee]

but if you're fit and healthy at age of 90, will you still choose to work for a few years at 70? Especially the most productive members of society. I didn't look into it, you can investigate, but there was a factoid floating around that the top 1% support 40% of all taxes. So if the top 1% - who might spend a lot of their time in education - work an extra 10 years at their option, this might create 25% extra value, or increase the take in terms of taxes by 10% (40 percent of 25%). So if you increase everyone's lifespan enough to increase the tax take by 10%, spending 1% of GDP to do so might be well worth it.

Also, as the richest spend a lot of their early lives in education, and afterward can experience certain network effects of experience, knowledge, networking, etc, perhaps those are ten of their most productive years. Think of Warren Buffett at 35 and 65.

This is a rather hasty, and incomplete analysis, and I haven't had the time to look at all the facts, but yes my line of reasoning is that as a practical matter that money can be "free".