@Nabeel_Ali
Thanks! Galaxy Note 8. Period.
@aliabid2
Nothing is perfect. It's all about requirements and preferences. Whatever suits your requirements best. But Xiaomi is starting to betray by overpricing stuff here, which is not very good thing for Xiaomi future.
@k-four-nine
The answer is there among my last posts in Xiaomi Fan Club. Settings > permissions > autostart. Disable autostart of those apps that are causing notifications issue.
But recommended settings for 2gb or lower ram budget phones for optimum performance is, that
1) you MUST disable background running/autostart for all non important apps (especially heavy apps like Facebook, Instagram, Snapchat etc), and only enable autostart/background running for those apps with super important push notifications.
2) swipe up/close unwanted apps occasionally and avoid multitasking by not opening more than 2-3 apps at once and swipe away the rest.
3) when you know there is an important notification coming soon on a certain app, just lock it temporarily.
Btw, you are asking way too much from a budget phone. Compare it side to side with a Qmobile, grand prime plus, oppo a37, Vivo, Huawei Y5 2017 and other direct competitors etc and then you will know which one is better.