I think C is way more accessible than C++. It's such a simple language that there are only so many footguns. C++, on the other hand, is a behemoth, and there are so many different opinions on "the right way" that it can be quite confusing. And with C++, you get all the baggage of C, and a bunch more.
With C#, you don't need to worry about memory as much, virtual tables are more sane, templates are more sane, etc. Basically, C# is what happens when someone adds a GC to C++ and cleans house. It's still complex, but there are far fewer footguns and a vibrant community. The C++ community is large, but I wouldn't call it "vibrant."