Based on my personal experience, I disagree. Of course it depends on the airline and the route, even FF status...

I've only paid for international F twice, once was a splurge trip when J was pricey and the other was an AONE4 trip which frankly based on our itinerary was stupid to do anything else. I do pay for J though internationally, usually BA across the pond, IAD-LHR-IAD several times per year to go back and see the folks.

In Club World as a BA Gold I can pre-assign my seats upstairs and usually score the better exit row or bulkhead seats where I've got as much personal space as in F. I'd even consider turning down an F upgrade if it was to a non-window seat! I can get CW for as low as $1800 return in a sale but usually closer to $3k with planning. For F I'm usually looking well north of $10k return. I've got 95% of the experience in J for 30% of the price. I've better things to spend that money on but I'm sure you earn a lot more money than I do!

I notice you are UA GS so on their flights you get a much better seat in F versus J. The same can be said for most *A carriers frankly; LH, SQ, TG, CX, LX...