You appear to be missing the main point of what nodes are for... it is nothing to do with quality of final result, but simply that a nodal system is leagues more helpful in a complex material setup because you only have to change a node in a single place for that change to be propagated everywhere else that node appears or is referenced in the material setup. Say for example that you have a stone material made of many complex layers, and one map is used in 20 different places within that material, across lots of different material channels. Now you want to change something about the scale of it let's say, or some other property. With Standard materials you would have to change that texture map by altering its controls / parameters in every single place it appeared, whereas with nodes you'd only have to change it once, in a single place. Also nodes often provide additional functionality that may not be available via the old approach, and that older way does not allow you to view the entire hierarchy of a setup at once.
Before we had a nodal material system in Cinema that was the number one request on the wish-list of nearly everyone that used the program !
However it is also true that in some cases a Nodal material is sometimes more work to set up than a standard material, certainly initially, and especially with simpler surfaces where not much map-sharing occurs, but the result is always infinitely more easily extensible than any non-nodal approach. It's about picking your battles - if you are making a very complex material with heavily entwined map inter-dependencies, or you need to make a heavily custom material that would be very difficult to achieve with Standard type then nodes are the best thing since sliced bread. But if you just want to throw a colour channel and a bump map on something, then Standard mats will probably serve you better and take less time to set up initially. The quality will be identical, or close to it in both methods.
Nodal systems are clearly the future in terms of building ever better and more flexible materials, and indeed Objects and other parameters in 3D more generally. With the recent announcement of Neutron that nodal approach is applied, for the first time in Cinema to more than just materials, and the power and flexibility of Cinema increases exponentially as a result. With that, models, and almost anything else you can think of can be infinitely procedural and extensible too !
The take-home message here is that you don't HAVE to learn nodes today, and nothing about the quality of your renders will change if you do or don't. But Nodes are the future, and you will need to know them eventually, so you might as well start now regardless, so that by the time they are de facto standard everywhere (and it could be argued they are already) you will know how to work with them !!