An interesting post.
As someone who takes from the FIRE community what is needed and leaves other components "behind" I can sympathize with you. Being FIRE and having a pension makes it easier to do this (take what works for me and ignore some "parts"). Example, my wife wanted a ***GASP*** big old F150 to drive back and forth to work, 8 miles each way... why? She's worked hard all her life, she sees herself as a "truck girl" and she had to "give up" her truck back in the day when we first got married, married young, and pregnant. In addition, she's not "in the same place" I am "on the path" mentally/emotionally when it comes to self-knowledge and awareness so, after 15 years of negotiation between us and hitting some other financial goals, we agreed and now she's got her toy.
I say all of that to say that you've had a fairly good run at this lifestyle, you've see more/other parts of it than many, and your POV may have shifted over time. It's almost if you've been taken out of the matrix, realized you kind of liked it in the matrix and want back in... no issue here/not my place to judge/criticize, I'm not a member of the internet retirement police.
Now, if you really do want that corporate job/BS or otherwise... have you considered becoming a project manager? I believe you were an airline pilot who FIRED and moved into real-estate? It might be hard to translate some of your experience into the hours of experience you need for some of the PM certifications (much of the requirements are arbitrary and only there to keep the bar/income potential of the certs high) but this is one of my specialties, helping veterans translate military experience into application experience, I could offer you the same (free of course). At the risk of being the guy with a hammer wanting to use it on every nail, I've found the PMP to be a real asset, allowing me to swap fields and move into work from home in support of healthcare/insurance, even though my 24 years of military experience was in Naval Aviation Maintenance, the cert still opens doors in nearly every industry.
I can see the truth in many of your posts, we (humans) need challenges that matter to us, we also desire status and, at times, things. In addition, we are all on different spots along the path and who are any of us to challenge the beliefs/thoughts/desires of others, especially someone "further on" down the path and as long as they are not "hitting us in the nose when they swing their fist". Also, some jobs come with perks you won't otherwise get. I don't get to go on-board aircraft carriers anymore, go out to sea with them, watch jets launch and recover, I've moved on, I'm beyond that and working to re-enforce other parts of my identify (and ultimately let all of that and the ego go but that's a LONG damn process...). So, I've "lost" perks but they don't mean so much to me that I'd take a crummy GOVT contractor job just to head back out to sea, I'm ok with it. However, there are some GOOD perks out there with some of this positions, many of them using OPM to cover lots of expenses, I can see the drive for some.
In summary, might I suggest a PMP/other project MGR certification, a remote position or one in support of a cause you care about (something I'm looking for, moving into support of a non-profit/veteran related position), something that has some of the perks yet still gives you max flexibility/freedom (two things that probably increase our contentment more than pay or another XXXX or ZZZZ). I've met lots of "older" PMs who came from other industries, I don't think ageism is as bad in this line of work.
Good luck on your journey down the path!