ERP is a difficult science indeed. I have seen lots of implementations done with many different products world-wide with more or less successful outcomes.
Odoo has the great advantage of being not only open-source but also “not compiled” since it is running on a python engine. This means it can be modified in any kind of way. Same goes with the templating using XML and Qweb.
Nevetheless, there what I call Good and Bad practices. Source code, modules, Python, API… all these are solutions but quality of the results as well as the durability of the solutions obtained can varry quite a lot and give many unexpected results depending on how modifications and additional elements are made.