I noticed in the comments everyone really likes them, but this is not my experience.
True, no leakage. Mine, I got it at least 6 years bacl, never put in a dishwasher and it’s as good as new. But whenever I used it for a hot beverage, everything turns bad in it so much faster than anywhere else. Initially I thought I was not cleaning it well enough. I cut a sponge to reach everywhere and I was doing it daily, with the thingy lifted like in the last picture. I concluded it’s not that. It’s like the perfect conditions are created for new life to appear in it.
I still use it all the time, but only for water. Which also turns bad, but at least it can hold for a day or something, depending if it is room temp or cold.

































This reminded me of time-banks.
It was used a lot in South American cities, at some point during the economic crisis of 2008. In practice it was working like this: people would declare in a sort of ledger what they can do and for how many hours, as well as what they needed and for how many hours. Everybody’s time was equaly valuable, no matter what they did.
It was going so well that they tried to accomodate stuff that would not fit in the time category, like renting a house. So they printed some sort of “contracts”/“money”. Government and mafia, printed counterfit and the project never recovered since.
(It’s been quite some time since I looked into this topic, so if I don’t remember something accurately, please let me know)