Depends on where you are looking. Have you tried this full index of SACD and BD-A releases? It is priceless with over 10,000 entries. Here:
http://www.hraudio.net/home.php
I never had a problem with Amazon or numerous other US or European, mainly British sites, unless they are OOP or limited to the Japanese market. But, if what you are looking for is not classical, then, yes, releases in other genres are indeed sparse, especially in recent years. And, many are remasters from analog, offering often questionable sound quality improvements vs. CD.
No, SACD player sales are not a barometer. That number is huge in sales because of all the Universal players that support it - Oppo, Sony, etc., etc. But, clearly, not all users play SACD on these players or have even heard of it. No way to judge that. I have never seen data on SACD disc sales. They are always inseparably lumped in with CDs.
Not sure if I follow why going Mch is limiting yourself. To me, it is the other way around. Mch players and systems also play in stereo, at least the last time I looked. You mentioned friends. Most of my audio friends strongly prefer Mch playback with discrete hirez Mch recordings as offering the best quality audio reproduction there ever has been to date with no signs of relenting. I buy nothing else, myself, and SACD has been the most prolific choice for that.
Incidentally, my Oppo 103 player is used only for ripping SACDs to my NAS, not for direct listening.
Never heard of PCM DVD, though there was briefly DVD-A. Seriously, not much happening with those ideas.
As a tiny niche within a niche, classical hirez Mch afficianado, I realize I am in a tiny minority. But, wonderful new releases keep on coming to satisfy me. I have over 4,000 SACDs on my NAS, predominantly in Mch, plus hundreds of BD-V's, BD-A's and Mch downloads. I do not feel limited or as if I am dwelling in the past.
I think your observations are a bit, no other way to say it, myopic.