I think this is only a problem when someone specifically promotes the movie as accurate representation. Like if the movie is based on real events. If you show real people inaccurately in can be defamation and it's a problem. Other than that I don't see any issue. It's cinema, every genre has its tropes and simplifications. In the end the main goal of the director is to tell a story. If he decides the story he wants to tell doesn't require historical accuracy than it's his choice. You have movies and shows that are built on accuracy (like Downton Abbey) and shows that don't (like Bridgerton). Both are fine in my opinion (as a concept, not necessarily as a show. I haven't even seen Bridgerton and got bored by Downton Abbey). For me the accuracy is totally secondary. I liked A Knight's Tale more than I liked The Last Duel.

Sometimes you just have to ignore those things. I've seen Fall movie recently and as a climber I have to say the climbing scenes were the absolutely dumbest, most physics bending bullshit I've seen. But the movie worked otherwise. I assume for non climbers this movie was even better. I see it at least partially as my issue, not the directors fault. I can't enjoy climbing movies like other people because I know to much about it. History buffs can't enjoy historical movies. Deal with it.

I would say most people do realize that movies are fantasy, not documentaries. Just what part is fictional differs but complaining that movie set in the past in unrealistic is as silly complaining that movies set in modern times are. Do you think Lethal Weapon realistically depicts work of police officers? Does Scream realistically depict a serial killer? People realize it's entertainment and don't complain about it. I don't know why once the movie is set in the past it requires announcements that it's "fantasy". Yes, it's a movie, you should know it's not real.