It's less work because you can streamline it into the rest of your baseball attention-paying processes. There is no value adding by maneuvering through free agent lists like you would in Yahoo! leagues. I already read MLBTR posts and monitor Twitter news, which give me all I need for LOD. If I happen upon news that some scrub I like is getting called up, then I quickly look up his availability. Once a minor leaguer I have is nearing 14 days in the majors, I make a move and add a new minor leaguer from my watch list. Aaron Hicks reached 14 days, so I flipped him and added Ian Thomas, who drew praise from Andrew Friedman in an MLBTR link. It's a system that doesn't actually take much involvement.
And you're right about lineups. Erasmo and Frias have been on the same schedule for a while, so every five days I just need to sub them in. And I do a little bit of shortstop mix-and-matching between Castro and Semien. In my Yahoo! leagues I have to constantly check to make sure I'm not sitting pitchers.