I did some observation where games can have low monthly live-RTP for several months. It means games can suck money for quite a long period (more people lose), before achieving monthly live-RTP higher than theoretical RTP (more people win). The problem is, gamblers cannot predict when the live-RTP will be favorable to them. When they see previous monthly live-RTP for game-x was 80%, this month live-RTP will still be unknown, it can even be worse than 80% or rebound to 110%. Sure, there are low RTP periods (cold) and high RTP periods (hot), but no one can predict the timing. RTP even more wildly fluctuates in weekly live-RTP and daily live-RTP, so there's no point in observing this data.
If you are interested in live RTP, there are casinos that provide the data. But for me, it only makes my playing session less enjoyable.