As mia pointed out, FHR is but one feature that makes up the total $550 value -- the first two being $400 in credits, and the next bunch being lounge access and hotel elite status benefits. I've definitely gone entire years of my Platinum card membership without using FHR, while still feeling like I got a good value for the card. But FHR can be nice to have from time to time.

I don't know if anyone has a comprehensive list of who participates in the various FHR/LHRC/Virtuoso-type programs, and all of them have properties that come and go over time. But anyone can go to https://www.americanexpressfhr.com/ and search for available properties, see the included amenities, and even see prices (which used to require you to log in as a Platinum card holder; checking from an incognito window it appears that is no longer the case).

To give just one example: LHRC shows 2 hotels available in Phuket, Thailand (a major resort destination). FHR shows 7 and offers a more extensive set of benefits. Virtuoso also shows a slightly different set of 7 with slightly different amenities. Personally since I have access to all 3, I check all of them (as well as other booking options, including booking direct, and the similar but less generous Visa Signature Hotels and Visa Infinite Hotels programs) when I'm considering booking a luxury hotel and see which offers the best deal, since there can be significant variances in the benefits offered. But I wouldn't pay much, if anything, for a standalone annual fee to have access to any of those programs.