The iPad Pro 2018 does USB 3 with proper power delivery. Flash drives work fine.
The iPad Pro 2017 does USB 3 with limited power delivery. Flash drives require external power.
The iPad does USB 2 with limited power delivery. Flash drives require external power.
The iPhones do USB 2 with limited power delivery. Flash drives require external power.
Apple uses Broadcom (and others) for BT & WiFi. Cellular will be Qualcomm in 2020.
Eug, you keep seeing everything I write as some sort of competition, rather than a collaboration. It's fine for you to clarify what I said if you think others in the conversation are confused; but it becomes tiresome when the clarifications are written as corrections, or are simply wrong.
For example Apple has its own WiFi and BT right now. Apple W1, W2, W3 provide Bluetooth and a somewhat limited form of WiFi. (2.4GHz, 1x1 only, only up to 802.11n).
So, yes, Apple's *known* WiFi offerings are not good enough for an iPhone right now, let alone an iPad Pro or a desktop. BUT the point, which should have been obvious to "one skilled in the art", is the question of whether Apple plans to keep it that way.
Given that Apple plan to design their own cellular modem, designing the other RF parts doesn't seem a particularly crazy assumption. BT is easiest, then WiFi, then Cellular, so it would make sense to work on a full-fledged WiFi-6/e chip, and have it ready, before cellular is ready.
Will those designs ship this this year in the new iPhones, iPads, and ARM Macs? Well, who knows?
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OK, to add to this for soresu.
The W parts provide the BT/WiFi for Apple Watch. So far Watch 3, 4, 5 jas all used W3.
The first round of AirPods used the W1, subsequent Airpods have used the H1 which (along with improving the BT part of the design, apparently drops the WiFi part as irrelevant to AirPods functionality).
Why haven't Apple been more aggressive about creating their own high-end WiFi chip? My guess is that everything is priorities. As long as Broadcom was reasonable in accommodating Apple's requests, whatever they were, Apple has plenty of work dealing with all the other silicon they've been creating and have lined up.
My personal theory (with zero evidence to support it!) is that once they were committed to their own cellular modem, the WiFi is a reasonable goal along the way. You have to create the same sort of primitives (Viterbi and ECC, Fourier, MIMO, now with one of the WiFi6 modes even the same sort of frequency/time blocks). You can use WiFi as a slightly less demanding learning project, with a bonus that at the end you have one more piece of silicon you can control. (The Project Zero write-up on an exploit that used the Broadcom driver is terrifying in what it reveals about Broadcom software practices...)