I hear you, there's definitely merit in simplifying or trying to refresh older works if done well, the problem is how demonized Marxism is in the west and the fact that a lot of older works are still valid today. I like Red Sails because it combines the new with the old in an approachable way. Many older works are still valid, and being primary works means it's less likely to be misinterpreted.

There's also the importance of studying history, and the process of how ideas came to be. This part is especially critical, Marx, Lenin, etc. aren't brilliant because they were born that way and had great ideas beamed into their heads from nothing. They existed within definite circumstances, and this shaped the development of Marxism-Leninism. Returning to the classics, and drawing a steady line of development to today, is the only way to get a great idea of what's going on.

For example, if you see a snapshot of something, it's very hard to tell what will happen next without also knowing what led up to it. Take any screenshot from a random movie, and it's unlikely you can predict the next scene. Now watch the movie from the beginning, and you can usually predict the next few seconds, maybe even major plot points. You'll also likely be wrong on some theories, or need to adjust them. That's a microcosm of the Marxist method!