I always think it is a bit funny whenever these stories forget that knights are almost certainly also nobles.
true but knights even if they are nobility are around the lowest if not THE lowest ranking form of nobility and most of these stories don't treat them as "historical knights" but more as high ranking soldiers
Actually, throughout most of time that the title/rank "knight" or similar was used, they were treated as not even quasi-nobles, often as just richer-than-normal soldiers, as the vast majority of knightly titles weren't hereditary and just a small favor of honor for personal merit or public achievement, mostly to ensure they could feed and gear themselves and their mount, so they could be called to military service at need. The title/rank of Baronet is the hereditary, actual-noble equivalent. Chivalric orders came much later and uplifted the concept of knights and knighthood with their Codes of Chivalry, but they still were fundementally just higher quality soldiers. Eventually they became more like social clubs for scions of real nobility and commoners who produced something of great merit, but the power and prestige in those later examples of knighthood was about who was in them and how hard it was to become a member, not about the order being nobility themselves. You can see this progression by looking at the companions of William the Conqueror as the original knights, then William Marshal or The Black Douglas as exemplars of the Chivalric Knight, with knighthoods like the Teutonic Order and Knights Templar as secondary examples, and people like Sir Isaac Newton, Sir Arthur Conan Doyle, Sir Elton John, Sir Christopher Lee, Dame Judi Dench, Sir David Attenborough, etc. as examples of the modern "elites club" model of knighthood (belonging to orders such as The Most Excellent Order of the British Empire, The Most Distinguished Order of St Michael and St George, etc. or being deemed Knights Bachelor as individual knights not belonging to any given order at all).