Xiaomi Redmi 9 is one of the most affordable phones available anywhere right now, and it's hard to find a better phone at this price point. The screen is of barely acceptable quality, the camera is disappointing, and the performance is middling at best, and yet, the Redmi 9 counters these with its superb design, good feature set, long battery life, and finally, the biggest ace in its sleeve — the ultra-affordable pricing. Let that sink in — the Redmi 9 starts at less than 9000, This alone offsets all of the flaws that the phone has in store for us. Or does it? Let's look at the the many, many corners that have been cut to achieve this pricing
DESIGN
Plastic is fantastic, especially on affordable phones, and the Redmi 9 once again proves that. The textured back of the Redmi 9 feels great in the hand and provides excellent grip when used naked, though I’d still recommend putting a case on. I actually quite like the textured back of the device, which not only helps with the grip, but also adds a certain "cool" factor to the device, and no, I have zero issues with the fact that I'm touching plastic. What’s more, plastic keeps the weight below 200 grams, which is admirable for such a large device with its humongous 5,020mAh battery. Don’t get me wrong, it’s still a big and heavy phone, but it doesn’t strike as such. Overall, the Redmi 9 is a joy to handle, despite its large dimensions.
DISPLAY
The display of the Redmi 9 is pretty average. Sure, it’s large and spacious with its 6.53-inch diagonal, and the resolution is more than sufficient, but it’s an LCD FHD+ display with bleak colors, low brightness, and disappointing contrast. The display is lackluster, and I didn’t enjoy it at all during my time with the phone. You will also have a hard time under bright sunlight, as it’s just not bright enough.
BATTERY
The battery backup, fortunately, is spectacular on the Redmi 9. With the phone's fairly efficient hardware, the large, 5,020mAh battery takes a long while to drain. You can rest assured it will last you for a long time; in my experience, two days of usage were guaranteed. In our custom battery tests, the phone lasted for a combined time of 10 hours and 14 minutes, which is one of the best results we've seen so far in 2020. Charging, however, is pretty slow — the 10W charger included in the box topped up the Redmi 9 in 168 minutes, or 2 hours and 48 minutes. That's slow, but then again, what else did you expect?
CAMERA
As far as the cameras are concerned, the Redmi 9 on the rear packs a 13-megapixel primary camera with an f/2.2 aperture and a second 2-megapixel camera with an f/2.4 aperture. The rear camera setup has autofocus. It sports a 5-megapixel camera on the front for selfies, with an f/2.2 aperture and a pixel size of 1.12-micron. But the performance of cameras are really disappointing.

Not much agree with above.