I'm glad that someone else feels the same way I do about OData and UI5. I've used both extensively (initially to learn more about them and then because I need to develop solutions that can be supported by customers) and neither is, well, ideal. The worst is that the SAP ecosystem is a massive echo chamber, filled with fanboys saying how wonderful OData and UI5 are. Really, they're not - UI5 is open source and yet no-one uses it. Why? And let me not get started with CAP (WTF did you give a product the same name as Brewer's theorem?).
There have been some attempts to extract some of the UI5 controls so that they can be used with React/Angular but I can't see those ever being adopted. I've worked with UI5 development teams that struggle with even getting the basics of Git and love using that godawful WebIDE, so I have no hope for customers being dragged away from SAP solutions to anything vaguely "industry standard".
Sorry for the negativitiy, but after 20+ years of SAP paying my bills (and paying them well), I'm even more cynical than ever.