> 2. Climate change won't end humanity itself, by all probability, people will be better off in 100 years even if we don't do anything about emissions. Better off in terms of life expectancy, poverty etc

That is a very specific version of "better off". There are many versions for which this is quite obviously not true. Anybody who wants to take a walk in pristine nature in Europe or large parts of NA needs to travel far to even have a chance of doing something resembling this. Not important you might say, well, that's your personal value judgement. Liberal democracies might also just be a temporary glitch and we're all back to dictatorships 100 years from now and I don't know how that would make us "better off" necessarily. Though that's not very related to overpopulation necessarily.

Even for your metric, life expectency has been stagnating in substantial areas. It's not a given that tech will solve that.

> 3. Water scarcity and hunger have reduced over the last 100 years

US water aquifers are approaching irreversible depletion, so I'd be careful with such statements.

> he had a bet with an economist Julian Simon that the price of metals would go up because of scarcity

Have you looked at the price of gold over the last decades?