everything currently requires you to bring the appropriate cable to connect it,
No it doesn't. Pretty much everything
came with the appropriate cable to connect it, and the cable mostly stays with the device. In some cases its a captive cable. When I pack up my laptop and go to work, I don't gather up all the USB cables from my desk and stuff them in my bag. I've got an ecosystem of spare mini/microUSB and lightning cables at home, at work and in my travel bag if I get caught short.
so why not simply replace the cables with the following:
Yeah.
That $60 of cables would do for my work desk.
But... about the same $60 again for my work desk, unless I want to have to unplug those cables and carry them to work with me every day.
Oh, and I've got a cinema display at work with a magsafe so I don't currently need to carry a charger every day - so add, what, $80 for a spare charger?
OK, so even with the old MBPs I needed to carry a VGA adapter around for presentations (yes folks, here in the real world HDMI in a meeting room is a bit cutting edge) but I'll need to replace that, too. Probably a couple more USB-C to A adapters too, lest somebody hands me a memory stick... because I'm leaving the
So, anyway, I sit down at my desk, plug in my charger, plug in my external display and... aw, snap! That's it for a non-touchbar MacBook Pro! On an Air, I wouldn't even have started on the USB ports yet. On a 2015 MBP I'd still have two USB ports, a thunderbolt port, an SD slot and either the HDMI or the second TB port free. Ok, maybe I've got a touchbar model with 4 ports - so I can plug in my ethernet and keyboard - then, that's all of my wonderful high speed TB3 ports used up. Practical upshot: I now
need a $200-$300 multiport dock - probably one for work and one for home - something that, with the old macs, was an indulgent convenience.
...and all for, what? 40Gbps TB3? I don't have any 40Gbps TB3 devices - and the market is not exactly awash with possibilities. USB-C devices? I don't have any of those, either, and the vast majority on the market are only 3.1gen1 - which will run happily from a USB-A port and, more often than not, actually ship with a USB-C-to-USB-A cable. What I
do have is a metric shedload of USB-A devices, with USB-A cables, including several brand new products bought in the last 6 months.
Thunderbolt 3 is such a huge step forward in every way
Not for a thin'n'crispy ultrabook that only gives the advertised life if you confine yourself to updating Facebook and light WP and will thermally throttle its CPU and mobile-class GPU before you get anywhere close to using 80Gbps of i/o bandwidth.
Anyway, Thunderbolt 3 itself isn't the problem here, except insofar that it has become joined at the hip with USB-C.
Thing is, USB-C - despite what the evangelists seem to think - is nothing more than a bunch of existing technologies that all work perfectly well over existing "legacy" connectors combined in a single connector. (It would be nice to say "and cable" except that is manifestly untrue because there are half-a-dozen different types of USB-C cable with differing capabilities). Now, that is a great step forward for phones and tablets which only have room for a single connector (and the mini/microUSB connectors are a fugly train wreck anyway) but its a massive step
backwards for serious computing devices that have plenty of space for multiple dedicated connectors (or, at least, would have unless you make them too thin to accommodate an adequate battery and cooling system).
Thunderbolt 3's speeds could be a huge step forward for high-throughput workstations hooked up to huge RAID arrays or specialist A/V hardware - but do you know what systems like that don't need? Ans: an all-in-one connector designed for mobile phones that does power, video, USB and PCIe meaning that
all of those have to be routed to
every port (or have a confusing array of identical ports with different capabilities and needing different cable types). What Intel are doing is quite clear - they're trying to sneak Thunderbolt in to the back door by making Alpine Ridge the go-to solution for system builders who want USB-C and USB 3.1gen2 capability (you'll see quite a few high-end PC motherboards with one USB-C/TB3 port and one red USB A port supporting 3.1gen2).
Apple had a very simple option - take the 2015 MBP, replace its two TB2 ports with TB3/USB-C ports (so the future-proofing would be there) and
keep the rest of the ports as they were. Maybe a couple of years down the line it will be time for USB-C everything, but we're a long way from that.
At least with the iMac, they've done that... but do you know what I'd find useful on my iMac? Ans: a DisplayPort or two so I could connect a second display without "wasting" a TB3 port that could at least be used for USB until/unless I need it for a future TB3 or USB 3.1g2 device. There's plenty of space (not that the iMac needs to be as thin as it is, anyway).
TB3 (the protocol) has its uses (at the high end) and USB-C has its uses (on phones and tablets - although those will probably be 100% sealed and wireless within a few years). Combining the two and pushing the result out on "pro" PC/Laptops only makes sense in fantasy post-PC world (we don't live in a post-pc world, we live in a post-buy-new-pc-every-2-years world - most serious work is still done on PC/Mac).