It’s my personal belief (only minor science behind it) that your body considers itself maximally healthy when it maintains a “reasonable” reserve of available body fat.
That seems to correlate pretty well with the “I can’t lose the last 10 / 15 pounds I want to lose” posts that are so common. There are also epidemiological studies that show all-cause mortality is lower in people who are 10 pounds “overweight”.
If I’m correct and the body is maintaining fat against times of privation or stress then it’s likely that getting rid of the last 10 pounds would require something less like keto and more like a classic calorie restricted, high exercise diet.
In opposition to my theory, there are people who struggle to even maintain a normal body weight on keto although all of them that I know of are athletes and many of them already seen determined to limit calories.