Is arrow notation for vectors "not mathematically mature"? Assuming that we can't bold our variables (say, we're writing math as opposed to typing it), is it "not mathematically mature" to put an arrow over a vector?

I ask this because in my linear algebra class, my professor never used arrow notation, so sometimes it wasn't obvious between distinguishing a scalar and a vector. (Granted, he did reserve $u$, $v$, and $w$ to mean vectors.) At the same time, my machine learning class used arrows to denote vectors, but I know some other machine learning literature chooses not to put arrows on top of their vectors.

Ultimately, I just want a yes or no answer, so at least I do not seem like an immature writer when writing my own papers someday.
A sign of mathematical maturity is the awareness that truth is invariant under changes of notation.
There's a reason I avoid it, which is that I hand write almost all my mathematics, writing in bulk, and it slows me down to write the arrows overhead. It helps me get down detailed thoughts quickly to use the same notation for writing those notes that I would use when I'm writing a full proof or reasoning from a prepared vantage point. Boldface isn't better, at least for speed (Maybe clarity? I have scribbly handwriting.), but knowing some calligraphy helps especially to cheat and have distinctions clearly hold within the text. Either way, if I don't have two sets of things using the same letters, I'll just use unadorned, pen-weight letters, and just draw them kind of formally clean. I have a feeling I'm not alone in this, and that the adoption of this practice would influence those exposed to its effect on an author's style, which would be another explanation for the large amount of authors there are that don't use arrows or boldface to distinguish vectors from other things. It's also normal if someone doesn't do that just because they don't feel the need to distinguish vectors' names from scalars' names, or have chosen some other notation sufficient to distinguish vectors and scalars in a formula, like a dedicated symbol and order of arguments for the scalar multiplication operator (useful for talking about rings as a module over themselves). The hat over unit vectors or just normalizations of other vectors, on the other hand, is useful for keeping your number of symbols small and showing by the name when things are related.