What are your thoughts on this?
Well, now, funny you should ask.
As it happens in the mid-late 90's I was working on the cutting edge of USB (then 1.0) development, designing the reference circuit boards and drivers for the new USB chips from outfits like Lucent (AT&T/Bell/WE). My company was one of those who helped develop the initial USB standards. So my thoughts on USB, including USB4, go WAAAAAAAY back.
USB has evolved through a combination of market pressures (for higher speeds, better reliability, symmetrical connectors, etc.) and technological improvements in silicon and software, to the point where it's no longer (in my opinion) anything like what USB started out as -- a way to connect keyboards and mice that was better than serial ports and cheaper than FireWire.
Now it's become a ubiquitous, generalized connection technology, so it's not at all surprising that they'd be shooting for still-higher speeds.
As for USB4, I'll wait-and-see how it pans out. 40Gbps is awful d@mn fast. I find it nearly inconceivable that they'll be able to do that reliably, using inexpensive cables, in Joe Lunchbox's living room. 10x the clock rate of the fastest CPU cores? A new data bit every 25 picoseconds? Holy Blue Light, Batman!
Those are my thoughts.