What is the most useless technology ever invented?

I take attendance by asking the students a question.

What is the most useless technology ever invented?

Lots of disdain for Apple products:

• AirPods
• iPhones without headphone jacks
• iPod
• iPod shuffle

Some people listed general one-purpose or unnecessarily one-purpose-plus-SMART things:

• blenders
• hand-dryers (x2)
• carbonation machines -- just deal with drinking "flat" liquids
• glasses headphones, but they cool
• smart fridge
• an iron
• any unitasker -- see Alton Brown's Good Eats
• fidget spinners
• juice keurig
• toasters
• toaster-oven (inspired)
• juicers

Some people took issue with the question or tried to hedge:

• I don't know (x3)
• probably something I don't know about
• any answer I give would probably upset someone
• How do you define technology?
• all technology is useful

Other people seemed to have a grudge, and express it via this question:

• those rainbow chairs on buses
• eye massager
• gunpowder
• AI
• Yahoo
• the U.S. Senate
• cars

I'll award the "yep, definitely" prize to "eye massager", which is certainly useless and probably also unwanted.

This post's theme word is rowel (n), "a small spiked wheel at the end of a spur attached to the shoe of a horse rider; used to goad a horse" or (v tr), "to prick, to vex." The attendance questions seem to rowel certain students.