At this point, Apple could release a line of $99 drink cozies and sell out 5 minutes after they announce it. The fact that people buy what Apple sells isn't really an indication of whether the product is good or not.
I didn't call it a "flop", I said it's status as a flop doesn't correlate to how good a product is. The Butterfly Keyboard never flopped, but it also never got a legitimate competitor. People bought them because they were forced to, same as they were with Airpods and arguably the Apple Watch.
I feel the same way about a lot of Apple products. The Magic Trackpad would sell out instantly if it got a new model with USB-C - but Apple knows they can ship more Lightning cables if they avoid it. It's part of the sinister math that goes into making you and I rely on Apple's constant... ahem, Innovation.
(I agree with you, for what it's worth - Apple is weirdly slow to update some of their products; AirPods Max stand out here as missing USB-C and the lossless audio of AirPods Pro.)
You're right, and it doesn't break compatibility with USB (curse the idea of MFi on PC) which is the important part.
Still, it makes my relatively-new Magic Trackpad 2 feel old and alien. Whatever reason there was for Lightning is lost me when I can't juice my peripherals up with the same cable that charges my Macbook.
I take it you mean flop differently than a successful product from a business and profit perspective. Like a comedian can flop around on stage in a hilarious bit of slapstick humor which you might call a successful flop. But the two hour comedy special the slapstick is part of might be panned by critics and audiences and that would be a flop of an entirely different sort.