Maybe if walking at a professional speed walking pace and lifting a 0.5kg dumbell for 1 rep for 1 set 🤔 so much context missing here

Nobody is lifting weights to burn calories

Not sure that's right.. competely depends on intensity and load

Why not do both?

I don't lift weights to burn calories so that's fine

But lifting weights/building muscle will help you burn more calories at rest. You should be doing both, one for your cardiovascular health and one for your musculoskeletal health

That's mostly incorrect depending on intensity. Lifting weights burns 200-600 calories per hour walking burns 200-500. Assuming no incline. So it's a fairly similar amount of calories.

You gotta read more buddy.