This has been a great thread. I need to do a breakdown for future updates and how much it costs so it will help you and others decide what to do.
I would've also said its never too late because of how they've made the game now. I think they know players (the vast majority which are core to casual) dont want to just play this exclusively so they give enough content each week available to play so a few times a week feels absolutely perfect now. You can play even more but then thats down to what you want to achieve.
They are finally reaping rewards of moving to a better underlying code so changes and hotcakes can happen much quicker.
The story needs a better way for people like yourself to understand the past better but once you get up to speed the story is actually the best its ever been. I have the books (they are awesome) - its the only books I read but it isn't like a story as there are many facts and cryptic elements in it that make things a little difficult to visualise it all. I'll find the best video from MyNameIsByf about the backstop on Destiny.
The grind was one of the things stopping everyone play this. Now they've tinkered the levelling and made all seasons available for at least a year rather than just that season means you can play for however much you want, which in turn you see more people on all the time.
Finally, crossplay should really mean we can finally all truly help each other.
I don't think there's even been a better time to either start or cone back to the game. The combination of the game's state, upcoming content known for the next 3+years and the way that FG people are helping out everyone now, its the best its ever been.