My sister’s boss has a stutter and for years didn’t have good fluency. He’s in his late 50s/early 60s and is a scientist who does a lot of public presentations at conferences etc. I didn’t even know he had a stutter bc you usually can’t tell. I asked him how he got to that place, and he said “I stopped giving a fuck.” So yeah, at least according to him, adopting that attitude could help. A lot of time people are more interested in the content of what you’re saying rather than how you say it.