i think when small stores gets big from online ads, and they need to accommodate the new demand from e-commerce side. Many online stores have a issues of keeping up and mess up with quantities in stock. when they upgrade and hire more as time goes by, they become more reliable.

I did not buy anything at Optic Planet for years, because they had a horrible reviews.
when they were selling trg magazines at $140 and gave them a chance. they have been really good since.
I still try not to order anything under 4 or 5 or low quantities items.