The name of Pixel 4a 5G easily leads to a common misunderstanding that it's a Pixel 4a with 5G.
Pixel 4a 5G looks like a bigger brother (screen size) with 5G of Pixel 4a as they share the same soft-touch polycarbonate unibody design. However, they don't have anything else in common. Key features like screen size, chipset and rear camera are all different.
In fact, Pixel 4a 5G actually resembles the Pixel 5 in many ways. Both Pixel 4a 5G and Pixel 5 have the same chipset & GPU, same camera and same network bands. Pixel 5 has more RAM and a more premium look with aluminium encasing with a smaller screen size.
In my opinion, Pixel 4a 5G is just a cheaper version of Pixel 5, but with a bigger screen. Who cares about the aluminium encasing body? You won't even notice after putting on a phone case. This makes Pixel 4a 5G a better deal compared with Pixel 5.
I would name the Pixel 4a 5G as Pixel 5a :)