I don't think anyone is saying she hasn't improved since she made her debut. Obviously, she has. But there have been significant matches that she should have played better in or won as she was the higher ranked player. Some tweaks need to be made to her game. Trying a new coach isn't all bad. She won't know what she can achieve until she tries.Coco Gauff's Year End world rankings:
2019 - 68 (first full season)
2020 - 48
2021 - 22
2022 - 7
Current - 6
Coco's world ranking has improved significantly each year she has been on tour. And she also won at Auckland just last month, which disproves your statement that "she will not be winning any of those tournaments". I'll admit that Coco has hit a rough patch since winning at Auckland, but let's not act as if she's full blown gone backwards like 93 US Open Capriati.