I had the same issue with Coolors last month. Those tools spit out nice looking squares but forget about actual use, like text contrast or lighting. What finally worked was picking just one color I loved from the generator and building the rest manually in my design file. I'd adjust the saturation and brightness on the fly until things felt balanced. It turns out you need to see the color in your own layout, not in a vacuum.
That part about building the rest manually in your design file is where I see it different. Those color squares from the generator give me a complete starting palette that already works together. It saves me a ton of time because I'm not great at color theory. I'll take that set of five and just tweak one or two shades directly in my project if something feels off. For me, seeing them in a vacuum first actually helps narrow down my options before I even open my layout.