It's not modern languages, it's Rust specifically - they didn't optimize for readability and ended up with a language that's hard to read.
Rust is plain hard and complex. There is only so much you can simplify that.
Like, you can make jet fighter easier by adding ways to automatically make some things so pilot doesn't have to do all the steps (like say Rust does with some of the memory management), but it will never be as easy to fly as it is to drive a bicycle, still need to learn how everything works and what does what
I'm here doing things like creating an object, iterating over some structure, building a simple function, reading or saving some data, making a small REST API - and while I'm doing these things I have to work with complex syntax and language semantics because the same language also caters to use cases that have nothing to do with the thing I'm working on.
'?' doesn't mean anything like what it means in every other programming language, and it's everywhere. It is so frequently used that you get used to it pretty quick, but it is very not obvious to a beginner.
Obscure #[blah(blah)] attributes attached to nearly every line of code in some places. Do those have meaning? Are they just hints to the compiler? You'd better hit the docs to find out.
Do I need a &mut Option<Thing>, or an Option<&mut Thing>? And how do I get that out, as a `opt.as_ref().mut()`, `opt.as_ref_mut()`, or &mut *opt`? Are these valid? What's the difference? Idk, it's inscrutable.
Rust syntax really, really sucks my friend.
Follow up to this example: let's say that I don't know the answer, what do I search for if I want to find out?
The only thing that keeps this from being as big an issue as it ought to be is that rustc’s error output is really, really good. Usually it tells you how to fix it.
The second part of your question is bad syntax however, I agree (but still, 90% of the unscrutability of rust is caused by its concepts imho).
That depends on what you want. Do you want the address to a mutable Option of a Thing, or do you want an Option of an address of a mutable Thing? The mental model you have of your code should make this rather clear.
It's a complex language with unique properties, and it's syntax was carefully crafted towards it's goals - high performance, close to hardware, no runtime, memory safety etc.