These "semi-pavers" are common for driveways / walkways in Germany. Most water utilities there charge you sewer fees based on the solid-surface/paved area of your plot, and therefore permeable paving literally saves you money ...

If you were to use them for a patio garden, keep in mind that the "filling" (soil / sand / gravel in between) tends to settle somewhat over time. This exposes the edges and creates a bit of a trip hazard; you don't want to stumble on it, or topple the garden chair when the leg slips into one of the small holes. You should expect to "refill" them (top them up with sand, vermiculite or compost) every once in a while.

I'm unsure I'd use it for a sitting area. For a permeable path, where you can have the "grass grow over" yet not sink your shoes into the mud in winter, they're quite practical.