I believe THC is still illegal in France. So it's mostly convenience - a certain base of weed users don't want to buy from dealers, or want the security of a well produced product - an illicitly produced THC vape can be dangerous [1][2].

CBD (particularly the terpene infused ones) fill that gap.

[1] https://www.independent.co.uk/news/health/vaping-cannabis-oi... [2] https://www.vice.com/en/article/xweejk/cannabis-vapes-pens-b...

Edit: Should also mention there's a market for the effects of weed, without the 'high'.

CBD does seem to have some minor medical benefits like some inflammation and pain reduction. It's not the miracle cure that the CBD pitch men claim though. Most of the affects are apparently placebo based though.

CBD has pretty awesome properties. For me, it kills or controls migraines very quickly.

I also use it when I get dental procedures, because it's not intoxicating like Ativan or similar.