@Amritendu,
With all due respect, I think these issues are a lot more common than you are claiming. Just because many people have less than 15 mbps on their WAN connection, no static IP devices, no Macs, no need to see a complete list of currently connected devices, etc. and don't notice a problem doesn't indicate a lack of problems on their devices.
For instance, I have a 300x20 internet connection that is sometimes up to 350x25 on wired connections in my home. It almost never goes above 150x15 mbps on my AC network and often dips below 50 up, sometimes going as low as 10. With an average speed in the US of 36x11, maybe the speed problems are less noticeable for most people.
I posit that most people (a.) haven't noticed a problem because they're barely utilizing the router, (b.) don't like to make waves and haven't complained, or (c.) exist in a perfect use case of exactly the right devices in a location 100% free of interference.
And please don't claim that things are easily fixable hardware flaws when they are likely due to poor design decisions or poor programming in the firmware. I've looked into the workings of the fimware on my unit, and it's a mess. What people have been asking for is a roadmap on getting the core features for any router firmware fixed, and the promised features implemented, because we've seen precious-few user facing changes in the supplied firmware recently, and we want to know if there are even plans to address our problems. If there is a big issue that is occupying the developers, it would be nice to know that too.