I did a grow with a Kind blurple in 2017. The plant grew just fine. The issue with the blurple spectrum is that, lacking green light, it was really hard to detect issues with the plant. I used special glasses but it was still a PITA compared using a "white" LED today.
And, of course, PPFD maps were awful compared to today. Below is the PPFD map for the Kind 600 XL, Series 1 light which retailed for $600 in 2017.
Blurple technology if antiquated and any light using it today will, at best, tend to be low quality because, in a race to the bottom on price, you've got to do everything you can to cut cost or you go out of business. The PC clone business was the same way in the 80's and 90's.