Focus on calories or carbs

What's your goal? Fat loss?

If so, stick with calories. Calorie balance (fewer in than spent) is what directly determines fat loss.

Macronutrients (protein, fat, carbs) are about nutrition. Nutrition is important to health. (Nutrition can *indirectly* affect weight management and fat loss via cravings or energy level, in the long run, but if you stick to the right number of calories, you'll lose fat, pretty much no matter the source of the calories.)

Fat and protein are "essential nutrients", a technical term that basically means you have to eat some, because your body can't manufacture them out of other nutrients. Carbs are not an essential nutrient: Oversimplifying, your body can manufacture them out of proteins/fats, if it must.

Some people find that if they eat "too many" carbs, they have more cravings and more difficulty sticking with a calorie goal. Those people may benefit from eating lower amounts of carbs. Other people find that their energy level tanks if they don't eat "enough" carbs. Those people should eat some. "Too many" and "enough" are somewhat individual. Some people have a medical condition, or a drug regimen, that requires them to monitor/manage carb intake. Those people should watch carbs. At the margin, there are some reasons that other people with special needs (endurance athletes, say) may benefit from managing carb intake, for performance reasons.

In the diet industry these days, there's a lot of trumpeting about carbs, mostly based on poor science. The industry needs things complicated, so we'll keep buying their solutions (books, programs, supplements, etc.), rather than reaching our goals without their help . . . ideally, they benefit if people see a quick win, believe the magical solution works, then can't stick to it long term, because then that consumer will come back and buy more stuff. It's a cash cow.

Carb restriction fits that well: It will usually result in a quick, big water weight dump up front, so quick loss on the scale. Some people find it beneficial and easy, stick with it long term, and succeed. Others, quite a few of them, see that quick loss, believe it works, but find it too hard/impractical for them to stick with permanently, so they become repeat customers for the diet industry.

If restricting carbs, helps you, do it. It does help some people lose and maintain weight. However, it's not a guarantee of weight loss: Think about it, if limiting carbs always causes weight loss, how can one maintain weight at goal? Add back carbs? Could. But a person won't have learned how to manage (and if necessary moderate) them.

I'm a believer in eating a sane number of calories, and getting overall good, balanced, nutrition. In that context, "too many" carbs would be so many that I can't get enough of the *essential* macronutrients (protein and fats), or so many that I exceed my calorie goal repeatedly. Otherwise, to me, carbs literally don't matter. I ignore them I hit my protein & fat minimums, hit my calorie goals most of the time, and eat plenty of varied, colorful veggies and fruits (which tend to be chock full of carbs).

During weight loss, 50+ pounds in under a year, I was eating around 150g carbs most days, when I look back on my MFP food data. Now, in the 5th year of maintaining a healthy weight since then, I usually eat more like 250g carbs. It's been fine.

You can decide how you feel about this question; others will offer opinions, but the above is mine.

I have lost 125 pounds simply by counting calories, nothing else. I of course am mindful I have a varied diet but beyond that it is calories all the way.

No reason to restrict carbs unless you have a medical reason or feel better eating fewer carbs. If anything, I'd suggest focusing on protein and letting your fat and carbs fall where they may. If you aren't feeling good or are hungry, adjust fats and carbs.