I like to leave them on my bike, but eventually they get lost.

My old theory was that if I ever have to air up at a gas station, or perhaps borrow a pump, I'd have the adapter. But in reality, that really never happens, and gas stations have been removing or hiding their air hoses.

I have, on occasion, worn out mini pumps, which one usually discovers when one needs them.

You can purchase push-on presta adapters. I haven't used one for years. In theory one attaches the chain to the pump, and it stays with your pump.