Well, the smartphone world is very dynamic, just like the garments i.e fashion industry. It changes at a rapid pace, hence it's rather difficult to predict the future!
2015: Displays got bigger while side bezels got smaller. Glass builds became more mainstream.
2016: Dual-cameras became the norm with "bokeh" effects.
2017: Notches and tall aspect ratios.
2018: Big batteries and screen embedded fingerprint readers. Face unlock also became popular in 2018, if I'm not mistaken.
2019: Multiple camera modules (w/ wide angle lens) and phones with folding displays. Gesture based navigation also became far more popular.
2020: No idea!
But if I've to take a guess, I'd say in year 2020-21 notches will be eliminated thanks to screen embedded selfie cameras, we will likely see more foldable phones and lastly, camera resolution will likely exceed 100MP on most flagships. Also expect to see screen embedded FPS on more lower mid-range phones.
If you want a good phone 'now' then consider the Mi A3. Otherwise, wait for Mi A4, Redmi Note 9 and Realme 6.
That's all I can say at the moment!
