A2-class microSD cards offer no better performance for the Raspberry Pi
The major problem is not disk write speed, which we can all agree sucks, but longevity and lifespan when used as a system boot disk and also containing /var and similar. The write wear leveling on a u3 microsd card is nowhere near as good as even a $50 consumer class ssd.Small single board computers should move towards m.2 2280 nvme drive support, or at least one sata 6 gbps interface.