I think the reason is much simpler, same as with 741 and 324 op-amps. These devices just came out at the right time. They featured prominently in the first crop of books that popularized a number of reference circuits among hobbyists and pros alike, and these reference designs have been endlessly copied since (including on the site where this article is hosted). Most people just don't know what transistor or op-amp can safely replace another transistor or op-amp in a non-trivial circuit.

In fact, for any non-trivial transistor or op-amp circuit you Google for, most of the designs you get are incredibly dated. And now, AI answers are reinforcing the same biases, so I guess we're gonna be stuck here for a long while.

>Today, the metal-can 2N2222 is still available from Mouser and DigiKey at around $1.88 per unit, while mil-spec hermetic TO-18 versions sell for upwards of $60 each.

$60 per transistor?? The military is getting ripped off by its suppliers.

Even the DigiKey price is nuts, you can get functionally identical transistors from China for less than a penny each.

Just so long as we remember to check it'll fit the need. I recently inherited a design that used some parts from the 70s and they were not up to the task. Drop-out voltages too high, gate threshold voltages too high; whatever spec could be violated was. Just because it's been used for 50 years doesn't mean it's the right part for the job

The 2N3904 is an old friend who has never changed. I've been using him since the 80s and he's still my first choice whenever anything general-purposey comes along.

No later than last week I was fishing in my boxes for two pieces of 2N2222 for a pet project!

BC547? 337? I think they are Texas devices, much popular too.

This is an interesting article on how open licensing can help ensure viability long after the original designer has left the game.

BC109 for ever!

Maybe in US. We had BC107-BC109 and BC177-BC179