The permission management of Android is a problem for a long time. The behaviour of an app depends on the morality of its developers. Unluckily, many developers are big companies which making money is their primary target and morality is little considered.
The problem gets bigger while it comes to the devices less power than smart phones such as TVs, or the devices that can get more privacy such as smart watches. The main permission problems of Android are:
You must give all the permissions to an app if it requests
On Android, you must give all the permissions it requests, or you just cannot install this app. This behaviour has been optimized since Android 5.0. But it is far from enough. Though we can also modify the permissions with tools such as Xposed, it is very difficult for normal users and not all the devices can use it.
There is also another way to solve this: provide a more trusted app market. Think about Linux: there is barely permission management in most Linux distributions. (User and group management don’t count, because a normal user can do many things). But most Linux distributions have a software repository which is maintained by trusted developers, so as long as we install programs from the official repo, we can think we are safe.
This may not a very big problem for a smart phone because you can install tools to manage it, or you just don’t care if your contact information is uploaded to some server. But when it comes to a smart watch, you are wearing it all the day alone, it can get much more informations than a smart phone. I cannot give those informations to a random app.
This is also a big problem for a smart TV. It is very difficult to root it or install custom tools. And a TV is in a family network, which is in the same network with your PCs and laptops. It can also get many private informations.
Many apps always running in the background
Android allows apps running in the background and awaken each other. It is really a bad design to allow an app awaken another one in the background. If I’m using an app and it open another one in the front of me, I can see it and know what is happening. Which is the only situation I may want such a behaviour.
Allowing random apps running in the background hurts performance a lot. You cannot control what the app is doing in the background. Maybe you will not notice this in a smart phone which is more and more powerful nowadays (or you may have noticed that your smart phone is losing power quicker and quicker as you install more and more apps). But the problem appears a lot while the device is not so powerful, for example, for a smart watch or a smart TV. This happens in my real life. My family bought a TV some days ago, but I cannot instal more than 4 video apps, or the TV will get stuck. It really sucks.