I decided to leave a review to help address the style choices made in this series, namely the "filter" everyone is referring to.
First off, the series is very well done. Acting, writing, progression and pacing. It feels like a Band of Brothers without feeling like it is copying Band of Brothers.
There's a few things to note. First, it isn't a "filter." It isn't like the show was shot completely live action and then just layered on with ray-tracing-like animations. It is a hybrid of live action and animation, yes, but that is different than what saying "filter" implies. Make no mistake, this is an animated movie.
The reason this was done was out of necessity. You can look up this series and see its been in production for years and was originally an 8-part live action series on History Channel. The issue was the cost. No one wanted to spend what would have been $150+ Million on a History channel series so it never got made. The writer, Jeb Stuart (Die Hard) did not give up on the project. One of their options was animation.
The team responsible for the series demo'd multiple types of animation and due to the stereotype of animation in America (that it is a largely comedic forum, e.g. simpsons, family guy) they went with this type of live action animation hybrid to keep the animation technique as serious as the subject matter demands.
Thank god for that. Because it would've been a shame to not have this series made. I understand some are upset by the animation, I get it, but I feel most are upset because they think it was an "artistic" choice. In reality, it was animate the series or don't create the series at all. This makes the animation more palatable.