I think I made up my mind when it comes to investing in ETF.
Dezooming kind of helped me: when you look at 5-10 years stock market graphs, everything looks exponential which it is. When you look at 100 years of SP500 in a logarithmic scale you can see that this is actually just following a 100-year trend.
Logarithmic scale:

Linear scale:

There are definitely crisis but usually they don't last more than 15 years whereas growth periods are usually much higher and longer.

Source: https://global.morningstar.com/fr/economie/ce-que-nous-ont-appris-150-ans-de-krachs-boursiers
The Earth is finite and we're into an out-of-control exponential curve (not only real economy). Population will still grow at least till 2050.
Stock valuations ultimately depend on expectations of future profits and economic activity. I think this should be OK till 2050.
I believe there will be more and more inflation and the cost of basic stuff will become more and more expensive, my cash needs to get into the boat. The world may change dramatically between now and 2050, but people will still need energy, software, healthcare, infrastructure, logistics, semiconductors, food, and communication networks.
Major international companies will keep leading the market for the next years. For now lots of them are from the USA, but the world is changing and I would like to look at some BRICS companies that may become the new giants : basically the GAFAM main competitors.
I've decided to stop purchasing the fuckin' "unités de compte" from life insurance and instead buy ETFs on my PEA.
- 70% Some MSCI World maybe FTSE All-World (developed + emerging in one ETF).
- 15% Some European companies that are not linked with government and exposed internationally (air liquide, schneider, ASML, stuff like that)
- 15% Stuff from BRICS countries