Dimas The Phone (3a) is an excellent device if you have low to average requirements. Small games (Clash Royale, Mini Metro, Balatro, …) run very smoothly and the device remains comparatively cool. I don’t need more demanding games. Social media, internet, maps and productivity applications also run absolutely smoothly, and here too you hardly notice any difference to the Phone (3). The camera is also absolutely solid, even if I don’t find the 2x zoom lens particularly helpful. However, it is very clear that you are “only” holding a mid-range device in your hands. Even if you take a closer look at how quickly apps open, whether there are hardly any noticeable micro-stutters, and the symmetrical, yet comparatively thicker display edges, you can see the mid-range.
The Phone (3) feels smoother overall, feels a tad more fluid and faster. The camera is noticeably better with better sharpness, even in low light, and a great dynamic range. More memory, Bluetooth 6.0, WIFI 7, thin display edges and, for me personally, always underrated: symmetrical stereo speakers. Makes every video and movie absolutely enjoyable, even in cell phone format.
If you value the special attributes of the Phone (3), then it is 100% the better choice. However, if you really only want to use the basics, take the occasional snapshot and value a stylish design, smooth operation and an aesthetically pleasing interface, then you will also be very happy with the Phone (3a).
If you consider buying one of these phones: I would actually wait for the Phone (4a). Perhaps it can catch up with the Phone (3) in terms of speed, camera, speakers and display and then it would definitely be a good alternative to the Phone (3), even if it will be inferior on paper.
EDIT: I forgot to mention the difference in size. It may seem not much, but it is undeniably noticeable that the Phone (3a) is larger :-)