Use only external Monitor on MacBook Pro
Solution 1:
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.