Yes Robin, we have all heard many times how you prefer doing things with out classes etc... (sometimes the hard way, just because code is inside a class and may not expose a newbie to every concept used inside it).
Your very biased attitude towards interfaces and objects is most probably what is holding you back. It seems you gave up on them before learning enough to see the real benefit in using them for what they are.
Being able to encapsulate a few features like shown in these examples is only scraping the surface. The C++ type system is built around having the ability to extend it.
If you need a feature/type that is not provided in the standard, you can make it. By using operators correctly you can create new types which leave your top level code (sketch) looking like nothing more than a C program. None of which has anything to do with the object orientated paradigm (that's all it is, an idea, a method of using classes a certain way, not a requirement).
The more you learn, the more you'll see their benefit (the learning curve isn't really a reason to hide it from newbies either).