What's absurd is the notion that every single person in every one of these industries must be a liar for FET to hold up...
Most of us in such industries, if not being in league with some conspiracy, would have be duped somehow by those that were in on the conspiracy in order for FET to hold up.
Things I work on in my career wouldn't actually work if the earth was flat and there were no satellites where I think there are. All this would have been designed and built, integrated and put into operation for no reason other than to perpetuate an illusion; not for the general public but for people like me who believe these systems to be actually functional, just so that "they" could show me simulations of ascending and descending payloads and fake the data transmissions.
Worse, the actual end users of these "faked" satellite comm, who actually experience the communications difficulties this satellite system is intended to solve, are fooled into thinking it solved by a satellite link when actually some other, clandestine terrestrial system must be doing the actual solving. Because however it's working, it works.
All that effort, to hide a flat earth reality?
All of our globe/celestial/gravity tools and calculators and tables and predictions -- they all work. I've witnessed the launch of payloads. Were they staged?
For 27 years, I've worked with systems above the earth, from line-of-site radar and data link systems operating in aircraft at 25,000-30,000 feet where earth curvature is a necessary factor to consider, and in geostationary and Molniya orbiting communications, and at no point was a globe earth ever in doubt. It's more likely we're all living in the Matrix than on a flat earth.
I don't say this to "ridicule your beliefs," because it's never been nor never will be my agenda to make someone believe the earth isn't flat. But there is a common sense aspect to this subject that must be considered. The "why lie" question? It can't be ignored if you're a believer in FET. A prominent aspect of FET, I see, is that it's not just a personal belief; leave me alone. It's driven by wanted to convince more people that they're being lied to. But so many people would have to be fooled that it would have to be Matrix-like. Especially those who do have experienced perspectives beyond looking for curved horizons or trying to measure if the earth is curved with lasers.
I've been to Antartica (for a day; military flight).
I've seen the Aurora Borealis from Hobart.
I've watched many rockets (NASA and SpaceX) launch from Vandenberg.
I watched a shuttle launch from Canaveral.
I point my DirecTv dish on an azimuth and elevation, else I don't get reception.
I had to learn celestial navigation as a midshipman, and demonstrate its use. It works.
I tested airborne early warning techniques for extending the radar horizon by exploiting elevated inversion layers.
These are just a smattering of life experiences that tell me I live on a globe, none of which would make sense if the earth was actually a flat plane.
You don't have to accept them. They're personal and aren't offered as testimony to evangelize for the globe view. But if you'd like me to take FET seriously (which sure seems to me what FET proponents would like), I'd have to be convinced that all of these (and more) experiences and observations were illusions, or deceptions, or misunderstandings on my part.