Which Android emulators or Android virtual machines run well on Ubuntu 18.04 and 20.04 or later?

BlueStacks is a really easy-to-use (and freeware, apparently) Android emulator that runs well on Windows or Mac, but isn't made for Linux.

I was able to get it to run in Ubuntu here by running it inside a Windows 10 virtual machine inside VirtualBox inside Ubuntu 20.04. In other words:

1. Install the VirtualBox virtual machine inside Ubuntu 20.04.
2. Install Windows 10 inside VirtualBox.
3. Install the BlueStacks Android virtual machine inside Windows 10.
4. Open it, log into the Play Store with your Google Account.
5. Install and run your apps.

But, the apps run really slow since it is 2 virtual machine layers deep. The first layer gets virtualization support with multiple cores, but the 2nd layer (BlueStacks Android emulator) does not get hardware virtualization support, and is therefore single-threaded and very slow.

Which Android emulators run well in Ubuntu?

I noticed this question exists too: What Android emulators are available?, but it's extremely out-of-date. The accepted answer is from 2012. The longest answer was last updated in 2017 and doesn't even mention BlueStacks, which is perhaps an industry leader today, and the other answers are all from 2012 and 2013.

I see two options:

• Waydroid.

  It looks promising, but it is buggy. Other users and I can't start it.
  Good thing to try here is Waydroid-Linux / Bliss OS which is in early alpha stage.

• Android Studio to run Android Virtual Device inside it.

  Installable using Ubuntu Make from PPA as shown below:

  sudo add-apt-repository ppa:lyzardking/ubuntu-make
  sudo apt-get update
  sudo apt-get install ubuntu-make
  
  umake android
  

  then launch Android Studio, click More Actions → Virtual Device Manager, create new device by Create Virtual Device and following wizard. Optionally enable graphics acceleration.
  Personally I use this method to launch some Android applications. I have not tested games yet.