Use only external Monitor on MacBook Pro
At the risk of being publicly wrong, this isn't something that's easy. macOS just wants you to close the clamshell to put off the screen. I understand you understand and reject this solution, but it's the only practical one we know of today.

I believe that people that used to do that at work with space for two large displays now may work from home and we'll see lots of changes as a result of common pain points, but there will need to be a change in the operating system to make this easy.

The closest you could get is using bluetooth / usb keyboard and trackpad but you'll lose the physical trackpad / physical Touch ID and the task bar when you close the lid.