I've never really needed ChatGPT for that myself, but what I see with my friends who are learning languages is that you're right about one thing: pronunciation isn't just about fixing your texts. That said, I think we're kind of underestimating what you can actually do with ChatGPT if you use it smartly. You can for example ask it to write little natural dialogues about stuff that actually interests you, not just generic sentences, and then read them out loud. That forces your brain to connect the sound with the structure. But it's true that without hearing someone else speak, you risk just learning your own default accent.
What worked for me with other stuff (I learned a fair amount of German just by watching gardening forums), that's exactly what was said: listen to real content about your passions. Like if you love manga, watch anime without French subtitles. If you're into cooking or sports, find YouTube channels in those areas. The thing is you're gonna hear how people actually talk, with the weird linking, the intonation, all that stuff. And you remember it better because you're following the story, not just doing exercises.
Really combine the two: ChatGPT to build you written content and dialogues about stuff you want, and at the same time hours of passive listening to actual English speakers. Start with videos that have English subtitles (not French) just so you don't completely lose the plot, and then you drop the subtitles. It takes longer but that's how it actually sticks.