I think you make some very valid points ukdoctor wrt the issue of whether travel is being paid for by an employer or out of one's own pocket.

All airlines with FF programmes obviously like to "tie you in" as much as possible. In fairness there are of course mutual benefits, but in the effort to reach the next tier, one can become blind to the fact that there are sometimes more advantageous fares - and often significantly so, as you point out - on offer with alternative carriers. Once the tier status is being 'bought', its true value becomes more & more questionable.

YohYohY's earlier thread which outlined the tangible & non-tangible (inc. the 'hit & miss') benefits was a good summary, and for me highlighted why I would never want to spend several thousand dollars purely to hit Plat, with access to F lounge at DXB and FC check-ins being the only perks I would find myself using. Op-ups are highly variable as we all know (and there have been various anecdotal tales of them even diminishing after Gold ....!)

All that said, if Plat comes in the normal course of events, then it's clearly more than welcome.