As far as legacy USB ports go, those USB-As can’t do what USB-C can.
...and
there's the sound of the USB-C Kool Aid being chugged.
USB-C is no more than good old USB 3, DisplayPort and charging moshed together into a single connector. It may be useful for phones where it is
necessary to combine everything into a single port, but on a laptop with plenty of space it just sells dongles and creates all sorts of confusion and complications by having a range of superficially identical ports and cables with different functions. (NB: even USB 3.1 gen 2 can run over USB 3 A connectors - you'll find 10Gbps USB-A ports on some PCs - USB over USB-C is just the same old USB, unless you've seen 20Gbps USB3.2 actually implemented anywhere?). Anyway, 5Gbps US3 is more than fast enough for all but the most expensive external SSDs - but apparently - although nobody wants to plug in the SD card from their dashcam or prosumer DSLR - people are queuing up to connect multi-SSD RAID arrays, high-end A/V racks and 5k displays to their entry-level MacBook Air. Right....
Between them, the MagSafe, TB2/DisplayPort, 2xUSB-A and SD slot on the <=2015 Air could do far more, without dongles/hubs, than the measly two USB-C ports on the new Air. Charging your Air while connecting to a data projector at a meeting when someone hands you a USB stick? Not a problem on the "classic" air and you've still got a spare USB for your pointer thingy or external drive... got the new model? Tough - it's dongles at dawn.
Or even if they'd used the smaller size of USB-C to put 4 ports on the Air and 6 on the Pro (oh, wait, that's not so good because although most modern CPUs have USB to spare, now you either have to find PCIe and DisplayPort lines for those extra USB-C ports or users have to play a game of "guess which port supports what?".
Folks, there's a reason why companies are
still launching new multi-function hubs that re-instate the old "legacy" ports whereas you can't get a hub with multiple USB-C ports for love nor money... USB-C is a solution looking for a problem and many, many people just need their USB-A and DisplayPort/HDMI back, whereas a one-to-many USB-C hub that does anything more than just feed USB3.1g1 to the downstream ports is far more complex than a good old USB 3 hub.
Yeah, you can convert USB-C to USB-A with a dongle... but for the vast majority of USB-C peripherals out there, which are still USB3.1 gen 1, you can equally use an adapter to plug them into a USB-A port without loosing an ounce of performance -
plus unless you bought the peripheral from Apple it will probably come with the adapter in the box.
Of course, If Apple had taken the sensible route - just replaced the TB2 with a single TB3/USB-C and kept the other so-called "legacy" ports fora few years more (which is what they did with the iMac and the Mini, like most PC laptops) then you'd have the best of both worlds... The nearest that USB-C comes to impressive is its support for one-plug docking (...because
two plugs is just impossible) and you only need... let's count... one USB-C port for that.