Yes for Microsoft Lists the default is a mobile app, but none of this has anything to do with why your app does not work in your corporate environment, that is completely out of Microsoft's ability to do anything about.
You mentioned you started with a blank canvas app and connected, which is great, but you can swap the type of form factor from Phone to Tablet after you create you item from lists.
But none of that, from what you typed is the problem, the problem is "you run into issues when I try to use it in my corporate environment"
This statement is not accurate
All this could be easily resolved if Microsoft simply gave us the ability to create a responsive default PowerApp rather than a mobile first powerApp.
Because you can swap it if you want with simply starting with the Phone Version.
But again this statement:
Before anyone suggests that I start with a Canvas App and then import the data from my Microsoft List but I have found that yet again - I am running into limitations imposed by permissions and settings that I have no influence over.
Has nothing to do with Form Factor 0.00% so I am not sure why blaming Microsoft for corporate limitations makes sense.
What exact limitations are you blocked by in your Corporate environment? We need to help you, possibly come up with a business justification to get it okayed for your limitations, but understand.
Pre-canned Templates or starting with your own all require connectors. They all require permissions, they all require the same exact things regardless of how you started.
So let's see if we can help you get passed whatever "issues" your environment is blocking you on, even if its helping you with a business justification and helping your IT team understand how and why you should be allowed to publish your app or create them in any way :-) you need.
