Certainly not all garbage, though IHG (and Hilton) are two of the worst. Marriott[1] and Hyatt[2] seem to be much more dependable, per literally thousands of posts on their Flyertalk threads.

BUT, the practical consequence is that seeing drastically cheaper rates on OTAs than direct booking is much rarer than it used to be.

[1] https://www.flyertalk.com/forum/marriott-marriott-bonvoy/206...

[2] https://www.flyertalk.com/forum/hyatt-world-hyatt/970090-hya...