💼 Stuck with a boss who takes credit for everything, thinking about finally quitting

I have been at my current job for almost three years, and for most of that time I genuinely liked the actual work itself, the team is decent, the pay is fair for the role, but my direct manager has developed a pattern over the last year specifically that has slowly worn down how I feel about coming in every day. Ideas I bring up in smaller meetings somehow get repeated by him almost word for word in the next larger meeting, presented as his own thinking, with no mention of where it originally came from. The first couple of times this happened, I genuinely assumed it was accidental, people do sometimes absorb an idea and forget exactly where it came from without any real intention behind it. But it has happened often enough now, specifically timed right before promotion discussions or larger project reviews, that it feels less like an accident and more like a consistent pattern I am only now fully recognizing after being too close to it for a while. I brought it up once, carefully, framing it as wanting to be more visibly involved in project updates going forward rather than directly accusing him of anything, and the response was polite agreement in the moment that genuinely changed nothing about the actual pattern in the weeks that followed after that conversation. Talking to a couple of former colleagues who left that same team previously, this apparently was part of why at least one of them left too, though I only learned that detail recently after specifically asking her directly about her own reasons for leaving. I am now seriously considering starting to look elsewhere, though three years at one place does feel like a reasonably significant thing to walk away from over what might sound, described this way, like a smaller issue than it actually feels living through it daily. Has anyone left a job mainly over this specific kind of credit taking pattern, and did leaving actually feel like the right call afterward looking back?