Although I have been AA Plat for half a dozen years (by actual flying), their policy of baggage allowance for elites (which includes Gold, which btw needs only 1MM for lifetime) hasn't changed anything for a single bleep, since long before they instituted that I became a big fan of "carryon only" flying. It wasn't baggege fees that did it, it was the AA/BA combinaion constantly losing bags when connecting at LHR. The choices were ship ahead or carryon only, and the latter was much less expensive.

Meanwhile, I have also been churning Citi AA cards, and given that I don't fly for work (ie, no flights paid by someone else), the miles I get from that are much more than the bonus RDMs for flying as an elite. So I wouldn't veiw that as a top priority of status myslef. (And, btw, not all partners even given bonus RDMs for status; even though BA and some others recognize AA Plat status in other ways, like lounge access, they do not give bonus RDMs for having that status, on top of not even giving 100% miles in deep discount economy.)

Once you're carryon-only, btw, priority check-in is only useful when flying somewhere where you can't do online check-in or kiosk check-in. Every year that's fewer places.

When leads to prority boarding. That's a whole lot of work for just priority boarding! You didn't mention lounge access on int'l trips. To me that's more valuable, except:

Once I'm 2MM, I'm mostly going to start using miles (since I won't need to fly paid trips to requalify any more), so then I'm mostly always going to do business class redemptions on long overseas flights, and flying in business (even on miles award or miles+copay upgrade) I still get lounge access whether I have status or not.

So it's a whole bunch of things you didn't list (beyond priority boarding) that are the things that 2MM lifetime Plat will mean to me. First and foremost, it's beter treatment (than someone with no status, or even with lifetime Gold) during irregular ops (flight cancellations, missing a plane, etc). It's higher pecking order (than Gold) for "domestic" upgrades, it's ability to book exit row seats ahead of time (Gold gets that too), and it's getting into lounges on days I'm flying int'l even if I didn't upgrade (or get a business award).

But of all of those, as a 6' tall person, the exit row is the most important to me, and I've already got that "for life", given that I passed AA 1MM some time ago.

... Meanwhile, while churning Citi AA cards (while they still allow it, and if they "liike" you) may be the biggest source of RDMs, another one (that works for multiple airlines) is to always choose to eat at restaurants that give dining miles through Rewards Network (fka iDine), which runs AAdvantage Dining, as well as dining programs for most other major US-based airlines. You don't have to spend more, just change how you pick where to eat (when you would be eating out anyway). As long as you're living in big cities in the US, it's not that hard (if you, as opposed to your friends, can choose where to eat, that is). And if you eat out with freinds, and they let you pay on a (registered) card for everyone (and then they give you cash for their shares), well, then you can earn quite a bit of miles from dining.

The thing about bonus miles is to be concerned about the ones you can earn repeatedly, not the ones you can only earn once.

Meanwhile, even if you never got lifetime status, even if all you get is hundreds of thousands of RDMs, well, then you can choose sometimes to redeem those for business class, and get most of the benefits of status on those flights that way.