Lookup tables are a method of setting parameter values for families in which the geometry does not follow simple geometric rules. They’re not a method of customising the software they are an inherent feature of the software.
Dynamo is widely used as a means of getting Revit to do things that the software does not do inherently, e.g. transferring values from certain built-in parameters which can’t be scheduled into user-created parameters, or to create geometric shapes which can’t be made using the standard extrusion, sweep, revolve etc….and more.
The API can be used to customise some aspects of the software if you know how (which I don’t, I’m not a programmer and not interested in becoming one).
But, again, for average users of the software you cannot change certain hard-coded settings and the view discipline settings are one of those. You cannot create curved pipes (you can create curved Pipe Accessories, Pipe Fittings, but not curved Pipes). Similarly you cannot create square-section pipes…and other examples.
So you might wish for the software to be fully customisable but as far as I’m concerned there are certain aspects which are not.
”Revit should be no different” - I agree but unfortunately that’s not the case.
“if the tools exist in the software” - unfortunately they don’t.
See this idea from 2017. Similar to your own wishes. Not yet implemented.