Why was Frankenstein easier to read compared to other literary works from similar time periods

A few years back I read Frankenstein for english class and it was great but I was surprised I was able to read and understand it pretty clearly as opposed to similar works from similar time periods that I hate reading because the old english dialect is really hard to understand like literally anything from Edgar Allen Poe. Even Jekyll and Hyde which I enjoyed, was very difficult for me to comprehend and sometimes in class we would talk about the chapter we read and I realize I had no clue what was happening which is weird since J and H came out way after Frankenstein so why is Frankenstein easier to read than it and other literary works?