That's absolutely right. In theory, the RTP of a slot machine is fixed and doesn't change. However, sometimes the game shows a high RTP for a day or a week, which encourages players to play with a higher chance of winning.
As for me, just like you, I don't really think too much about it, because honestly, I've tried playing games with high daily RTP several times, but I only won big once, so I think it all comes down to luck at that moment