As I said upthread, I don't believe in dieting in the weight loss sense of the word, but it is confusing to know what do do OP - all of the diets you are considering can 'work' for weight loss...
Starchy/white/high GI carbs, such as bread, rice and pasta generally have only one purpose to serve for our bodies - they give us energy. If you are planning on doing something very active shortly after consuming them then all is fine. But most of us don't and most of us consume far too large portions of these foods (usually with fatty/sugary accompaniments). These carbs are effectively converted into sugar once digested and if we don't use them for energy more or less immediately, they get stored as fat. In addition, eating them as the main part of a meal (white toast and jam for breakfast for example), our body screams hungry fairly soon after because although you have consumed calories, you haven't had any nutrition and you body recognises this. So there is a good chance you will reach for more food and mid morning, a good chance that it will be more carbs and sugar and the cycle continues.
On a low carb diet you are forcing your body to use fat as its source of energy, also, as a matter of course you are reducing the amount of processed foods and sugar you consume so it is by its nature a low sugar diet. Many people find it easier to stick to than other diets because you still get to eat delicious things that we have been conditioned (by low fat thinking) to think of as treats. You can feel very satisfied eating this way and sustain it for lengthy periods. However other people find they get brain fog, feel ill and over time, miss the carbs. It can be difficult to stick to in situations where meals are out of your control. It also involves cutting out lots of high carb veg, and most fruit, which others struggle with. People falling off the low carb wagon often do so in spectacular style and regain weight very quickly, your body will grab on to the carbs it suddenly starts getting and build its fat reserves back up asap.
On a low fat diet, you are invariably taking out the high calorie foods that form part of your diet and it is this that leads to weight loss. However, fats (unlike carbohydrates) are essential for efficient repair and function of our bodies. Over time,on a low fat diet, health will suffer - it is likely to be evident in your hair, your skin, your nails, your mood, your digestion and concentration levels. This is mainly to to a lack of essential fatty acids - the good fat you get in oily fish, avocados, nuts, seeds, olives etc, but there is mounting evidence to show that saturated fat also isn't as bad for us as we once were told. Also, very importantly, you are taking out a source of food that provides high levels of pleasure and satiety, which creates a strong sense of deprivation, making it a hard diet to stick to for long. On the sugar front, if you are eating low fat foods that in their natural state are high fat then you are likely to be consuming more sugar or sweeteners and less nutrients.
A low sugar diet depends on how strict you want to be - technically, a full on low sugar diet would eliminate fruit and starchy carbs so, as I said, isn't so different from a low carb diet. However there is a scale - you could just cut out any food with added sugar, including minimising processed/starchy carbs and this would actually be a change we could all do with making - it will lead over time to weight loss (if someone is overweight to begin with). Not as quickly as a 'diet' but more slowly and effectively. It would also provide lots of health benefits, given all we are learning about the negative effects of sugar. You could then still eat things like root veg, beans, pulses, fruit, a drizzle of honey or dried fruit, which in practice is much more manageable than strict no-carb. It doesn't force your body into ketosis (the fat burning mode) that true low carbing does, but it gives more satisfying, nutrient dense food and - providing you don't regularly overeat (key on any of these diets that don't count calories), less calories.