Yeaaaaaaaaaah I can see it, I quit shortly after Fortuna came out so none of the modes were too far out there from what I knew at the time. I mostly just went through the quests and looked up where to get the new warframes on the wiki, then would engage with that content until I got the frame which was usually enough to become passably familiar with it. In a way, it's nice that the content drops are so siloed off because it means you can go do all of the eg Railjack content and can just focus on that until you're done.

On the other hand, if you wanted to get caught up so you could actually play the newest event that was active until like a week ago, it meant doing like 20 hours of narrative quests in a row.