I think OP it's about reading the research yourself. Everyone on here will have a set opinion , CICO is science but people who trot it out as a catch all pay little attention to the fact that not all calories are equal in terms of their affect in your system.
You could follow calories in calories out by eating oranges all day and nothing else....hardly going to be healthy is it ?
Look , yes personally I am keto, strict keto, lost 8 stone and have kept it off. However that's because I have a metabolic based disorder and have to account for that, other people do well on slimming world (my dsis is doing weight watchers and it works for her ).
Noone else truly knows your body and how it reacts. Noone can say categorically that keto or low carb or basic CICO can work for you. It's all very well quoting "it's science " but actually there are multitudes of studies showing multitude of things because ultimately we all have different systems , competing conditions etc etc.
I for example eat well over my calories out, particularly currently where I am tied to my desk and laptop all day, I have still lost weight (which granted I don't currently want to).
Keto works for me both because I fit the model of research but also because it fit my natural palate, my natural way of eating. It's not magic. It's just a fit for my profile.
For my dsis and dm if they start eating fat laden foods they find they can't stop eating them and overindulge. For me the same thing happens with sugar.
Look at the research yourself , if low carb is for you then consider magnesium (which in fairness due to the degradation of soil quality over the last few decades we all often lack) it may help with the constipation, I do and I am never constipated (I was a huge amount whilst eating a traditional diet...family history of diverticulitis as well...although I own I know little about the genetic effect of this so could not be related ).
Everyone will offer you a magic wand and there just isn't one, it's what works for you and your body.