They were pushed by some influencers and had somewhat popularity, then some influencer had their car catch fire and their Stanley cup survived, that went very very viral on TikTok.
And now I see generic Stanley like cups being sold in grocery stores. A true staple of virality
Stanley is a brand that makes things like thermal mugs. They were quality and lasted for years, but weren't designed with looks in mind. They were favored by tradespeople because they're hard on stuff and it just works. (I knew them for thermal mugs that held coffee.)
For reasons unknown to me, influencers got a hold of Stanley mugs, with a straw and handle. They became very popular. The company now makes them in many different colors and some people decide to collect them.