It is the entire reason they cant even talk at school. Did you forget??
If we look separately at why they don't communicate at school, it's more Kyotaro's excessive caution to avoid any possible risks. This is caused by fear of the consequences related to her work, both for himself (they may forbid the relationship) and for Anna, but this does not mean that Kyotaro is not overreacting here, especially when he prefers them to behave like strangers. In other words, he doesn't really hang out with friends at school and simply adapts boundaries to his communication style.
As for that, yes, Anna's career only plays a role in why he ignores her at school. The conflict itself has nothing to do with their careers, and in order to resolve it, they don't even need to reveal their relationship or anything like that. It's just that Yamada, despite feeling lonely, put up with it, trying to support him, because she understood his position. And then it turns out that he didn't go to school that day. Meanwhile, when Kyotaro was dragged home by Moeko, without trying to defend himself from Momo by saying that he wasn't studying (Kana didn't go, saying she had work to do), he only thought of her in order to avoid misunderstandings, when there was an opportunity to say that he wasn't busy studying so that she could come later, for example. Nothing prevents them from being there. And then, when she contacted him, he felt guilty that he wasn't studying and gave priority to protecting himself.
Anna's career doesn't have that much of an impact here. If it were a situation where Anna's job simply left her no choice, I would understand why it was mentioned here. But every time some drama happens, some people here start using it as an excuse to express their resentment at her choice of who she wants to be as the cause of everything, devaluing the other problems that they both has. It's as if Yamada will leave her career and everything will be fine, even though the problems and fears won't completely disappear for both of them, and at this stage, neither Kyotaro nor Anna want that.
In any case, that's not the main point of the answer. It's just that user hopes that the story will continue and continue, without Yamada being an actress. Who Anna is is a fundamental and integral part of the story and one of the main drivers of the story, on par with Kyotaro's “healing” and their relationship. And people, because they don't like some aspect of the story based solely on that, simply pretend that it's not important.