I have seen these used, in particular at our local hospital, where they've used concrete ones because its a parking area - I can't say its particularly attractive to look at though, but then, there are cars driving over it, so the grass is patchy, non existent in parts and long and weedy looking in others. Not something I've recommended to people for hardstanding in their front gardens, although it does comply with new legislation regarding porosity and drainage requirements.

If its what I thin it is they've been around for a while - main use seems to be for large public parking areas on grass, where they prevent the whole area churning up into mud very effectively. The area looks less unattractive than concrete. If its something different I dunno...

They have a lot of uses. If used in a busy area they do get worn down, but, in a private driveway with not so much traffic can look good.
The purpose is to allow drainage of rainwater into the ground beneath rather than it all running off a hard surface, into the drains and causing flooding downstream.

Look awful but do allow for parking in busy areas. The grass is never going to look happy. What are you thinking of using of?

I thank you all very much. My idea Moon growe was to use this material as a matrix to make a grass garden pathway, my apologies for not mentioning that before.

Doubt it would look good, as already said Loosestrife, the grass just grows up through the holes you an still see the 'pavers'. Much better to just create a solid path...

They have been in use in various forms here in Arizona for around 30 years. None that I have seen are very attractive, or even come close to providing a good lawn in the spaces.

I think that the problem with a garden path would be of uneven wear although if it does not get a lot of foot traffic this may not be great. People tend to walk along a specific line along a path, mostly in the centre. This would get the wear whilst grass would grow along the rest of the path. I can be mown of course. The use of these pavers would give a generally nice green path without people getting muddy feet.
If I was going to be creating paths again, God forbid, then I would consider this idea as an option.