I appreciate the candour about where your expectations for Marriott lounges generally came from. It's good you came here to clarify before you book a trip's worth of hotels at other Marriott brands and are shockingly disappointed.

Yes, indeed, RC hotels do not give elites access to their lounges and their lounges are significantly higher grade than you will find at Marriott's other brands that include elite lounge access as a brand standard. My understanding is that some lounges in the US offer powdered eggs for breakfast and have a paid-for honesty bar if they are open at all. This is probably the lowest end of your expectation. At the highest end, you've got SE Asian cities like Bangkok, KL, Jakarta, Singapore, Ho Chi Minh etc. where multiple hotels of varying Marriott brands offer a full breakfast (often in the main buffet restaurant) and hours of alcohol along with food that makes a decent meal in the evening. None of these will match your RC experience in Qatar I'm certain but most would not be guttingly disappointing. Bear in mind that RCs can charge something like USD150 a head for lounge access on top of the room rate for what you experienced in Qatar while the difference in room rate at other brands is perhaps nearer USD30 for an executive room with lounge access for guests without elite status. That price difference alone should give you an idea of the level of service provision in these lounges.