Significantly but not fully in all cases.
The example is an iPad which is not of the USB-C PD type but is USB to Lightning, if you connect an Anker product non-QC capable of output upto 2.4A, the iPad could draw about 2.3A, so if you connected an Anker product with a 2A output it will be little less than fastest possible at 2A (not 2.3A).
So the default fallback for QC is 2A. So if say you have a non-QC 2.4A port and a QC port, in some situations the non-QC port would be faster.
- recharge is generating heat which competes with the device gpu and cpu so often what you find is if the tablet is on and particularly being used, the Amps drops dramatically often to <1A. This is why the fastest recharge comes from turning off the device.
- the fastest charge is when the battery is <80% so if device nearly full you'd be drawing <2A anyway.
So this is a half full / half empty point. 2A is nearly 2.3A so you're not losing much, or its not 2.3A so its not the fastest possible charge.
Some Anker products (non-QC ports) output 2A, some 2.4A, some 3A per port. But QC is only fallback to 2A so in some cases QC is slower than non-QC.
Reminder: there is a fixed overall power budget so in multi-port chargers you might get some congestion so lots of ipads could end up charging slower, this is charger dependent. Powerport 2 has no congestion but as you go up the sum of the maximum per port is less than the total available.