I have a lab diamond that I chose because of the ethical side (and because it was cheaper!). Its completely indistinguishable from a mined diamond unless your a jeweller looking for the marking they give to distinguish it (because otherwise they are a threat to the price of mined diamond)
A lab diamond offered me the opportunity to have a much higher clarity, cut, colour etc then the equivilant mined thus my ring looks the better for it.
A lot of the argument comes that Lab diamonds don't hold value as well (simply because people know they are lab only due to the marking), which is somewhat true. But anyone who has ever tried to sell a mined diamond, return an engagement ring etc will know that the value of all of them absolutely plummets the second you leave the shop. My best friend was offered about 15% of what she bought the mined diamond ring for 12 months prior and was considered lucky. The worth is always sentimental mostly
It's the same durability as diamond which was a big factor for me, I love coloured gems but it needed to withstand me bashing it about. There's no reason you couldn't pass it down a line if you so wanted
I'm not massively anti mined diamonds but get frustrated at a lot of the false hoods. They are both chemically identical, they are both real things in their own right.
The equivilance of a fake rolex that gets bandied about is poor. Its not a fake anything, it's also identical in quality, and endurance. It's more like having a different brand of watch then a back market poorly made version of a brand.
You'll find a lot of the anti lab movement is encouraged by mined diamond stores saying women will be embarrassed to have them, their friends will judge them and only mined diamonds are romantic. Its exactly the same marketing that pushed diamonds into the industry in the first place and tried to make it the norm that you had to buy a diamond only, equivalent to 2 months wages other wise your fiance will be the laughing stock of the village and she would know you didn't really love her.
Discussions about the potential eco issues, and about resale value have some merit but the reality is a lot of it is nonsense.
I'll show you what an online mined diamond store says is the reason they don't stock them (note there aren't concerns about quality, durability or attractiveness!)
Ultimately some people have a gut reaction to the idea. The diamond market is invested in keeping prices high so a lot of the marketing is frankly bizarre