Yet people use daily to manage 10k-100k+ servers/devices.
The term "scaling" has very different meanings depending on context and how one product scales is very different from another.
You could setup a context that favors push vs pull and vice versa, you can also see different products scaling well or not depending on slight variations in context and implementation.
I am highly dubious that it would be possible to manage 100k servers, specially to do interactions with large numbers at a time. The way tower collects results in a thread pool, assuming success, simply does not work at any scale. I tried and tried. I fixed many bugs and got to about 4000 hosts before changing to another platform.
If almost every server is reliable, I am sure it would work fine. That is not going to happen at scale.
The term "scaling" has very different meanings depending on context and how one product scales is very different from another.
You could setup a context that favors push vs pull and vice versa, you can also see different products scaling well or not depending on slight variations in context and implementation.