Samsung Galaxy M21 6 GB RAM\128 GB storage memory is the best non-chinese budget smart phone right now (July 2020). Read on for further detailed answer and justifications!
I have been searching for best budget mobile phone to buy since couple of month (all brands) , the top contenders which came were Samsung Galaxy M31 , Poco X2, Redmi Note 8 Pro. All of these come around Rs. 15000 to 18000. On doing extensive research and comparison of various Youtube videos I realized it is best to go for Samsung M31.
However there was a new launch as well from Samsung with Samsung M21. M21 offers 3 rear cameras against 4 offered by M31. The primary lens is 48 mega pixel in M21 against 64 megapixels in M31. The price gets cheaper by 2k for M21. It's a bargain and the difference in specs do not account to much unless you are a professional photographer (who will have a DSLR anyways).
Both Samsung Galaxy M31 and Samsung Galaxy M21 are successors for Samsung Galaxy M30s, which was immensely popular and huge hit due to it's monster 6000mAH battery. Samsung stuck with the big battery theme and continued to provide big battery in subsequent budget phones as well (M31,M21).
Samsung has identified the success formulae for Indian mass consumers by providing a big battery, descent camera and a very competitive price. Samsung has roared back in the mobile phone market in last 2 years. Remember there was complete Chinese dominance 2 years back, with Vivo and Oppo and Redmi taking more and more market share.
Another best thing about Samsung is, Samsung creates displays and camera lens in-house, so what it means is, a Samsung mobile will have display and camera lens of Samsung brand (most of the time). This makes a lot of difference against chinese brands where they use different brands display and cameras. Example a Redmi phone may use display of Brand A, and camera lens of Brand B, and Redmi is brand C. It makes a big difference in look & feel, hardware compatibility as well as usage & durability if the mobile phone has maximum same brand components.
Finally, we all know the reputation and brand name of Samsung. The history of Samsung in mobile phone industry right from the days of 2G networks around 10 years back. All this adds up to go for Samsung more and more!
P.S. There is a common notion & perception that a big battery makes a phone heavy & not easy to use. Well I have actually played with Samsung galaxy M30s, and it does NOT actually feel bulky, as Samsung has done a great job to balance weight distribution & has a great form factor.