Pens
I like pens, they are low maintenance, have a relatively long shelf life, require no external energy source, and easy to manufacture.
Pens, are a perfected product, like the calculator, or A4 paper.
Sure, one may say they are reinventing I where
But except of fancy packaging, it wouldn't differ by much.
Pens can't really be marketed, the "sell me this pen" cliche exists, but is more of an heuristic, let P be a pen's price, for all where .
In a world where everything is a subscription, forks become independent companies, and full of copycats, perfected products, like the pen, are a breath of fresh hair.