It depends on which carrier. On UA, I have to say no way. The only US carrier that IMO still gives you something relevant for its top tier is AA. As for the other carriers, I know for a fact that SQ and LH do give you tangible perks for being PPS and Senator respectively. BA is also known to pamper their Golds. I guess some of the other premium carriers like CX also make it worth while to maintain your status.