Proper wood will last 10-20 years, depending on climate:
https://homeguides.sfgate.com/can-wood-last-rot-raised-garden-wall-104550.html
“Untreated lumber, such as pine, is the least durable and is not recommended. It will warp and begin to rot within three to five years. Cedar and redwood are naturally resistant to both rot and insect infestations, which is why they’re often used for decks and fences. These materials will generally last 10 to 20 years in a raised-bed garden.”
Very expensive, like 10k for 10 raised beds of 5 m x 1.2 m:
Better concrete:
Modular steel:
Straightcurve modulaire plantenbakken boxline – box lang deel gegalvaniseerd staal
Holland Gardening 