Yeah, if luck is good, everything works perfect and long lasting. Repairing shops lack patience.
If you search internet, even Galaxy S8 and iphone 7 users are facing many issues, that too speanding more than 80k. So if someone faces some issues in a 20k chinese top branded phone, its no big deal.
If an 80k phone lasts 4 years, then a 20k phone chinese branded phone should last 1 year to maintain same price to durability ratio.
Mostly chinese brands phones work fine for upto 2 years, so they crush iPhones and Samsungs in price to durability ratio, as well as price to user experience ratio.
Morever, in real world usage, there is hardly any significant durability or quality issues in top chinese brands considering the difference in prices.
Did you try turning off auto brightness and setting contrast to standard in display setting?
Its not due to 720P display, its mostly software bug, but even playing 360 VR on an entry level phone with minor stutters is not an issue, as most others will not play 360VR at all due to lack of gyroscope. lol