I don't think this is a very productive pathway, and it will take a long time. Rust and Assembly is also probably a poor choice for somebody who is starting to learn web dev, and an especially poor choice to learn before flexbox.

I would say: 1. HTML 2. CSS 3. Flexbox & Bootstrap 4. Javascript 5. React

I disagree, Rust and WebAssembly are both two things that are growing quickly and taking advantage of that right now would be a good idea (Since they can both be used together in Web development) and I was just giving him a list of things he should learn as a web developer in general. He can go at his own speed and learn each language and frameworkwhen he wants to at his own pace but it's not a bad idea at all to learn all of that.

Rust is cool...I question the feasibility of suggesting Rust in a list of things for a beginning web developer to try to learn.

Rust + WebAssembly may be a little more difficult but they're both languages that are growing very fast and being able to take advantage of that now before they get bigger then they already are is a great idea long-term. It may take a while but is it better to learn something fast or well?

Neither one is foundational to web development. If you were to push most beginners to Rust, they'd likely quit before ever tasting success. The "fast or well" equivalency is a false one. Rather, a beginner should focus on learning the basics first. You don't put a first time driver in a Ferarri...Rust is a Ferarri.

I never said they have to learn all that all at once... I was simply giving him a list of languages and frameworks that would help him in the future.

You did, however, specify an ordering placing Rust and WebAssembly ahead of your list of frameworks.

Sure, i already started form HTML, and it's so interesting!Thanks a lot.

No problem :) out of curiosity what do you currently use to learn web development? Something like Sublime or VS Code would be good options if you're looking (I recommend Sublime but it's up to you).