Frequency is the deciding factor
Full body 3 times a week gives each muscle 3 growth stimuli, which is ideal when your total sessions are limited. If you only lift twice a week, full body is the only way to hit everything twice.
Full body wins if you train 3 days a week; a split makes more sense once you can commit to 4 or more sessions.
Both build muscle if weekly volume and effort match. Train 3 days a week or fewer and full body is best because it hits each muscle 3 times a week. Train 4 to 6 days and an upper lower or push pull legs split lets you add volume per muscle without 2 hour sessions. Beginners should default to full body for the extra frequency and squat and bench practice.
Full body 3 times a week gives each muscle 3 growth stimuli, which is ideal when your total sessions are limited. If you only lift twice a week, full body is the only way to hit everything twice.
At 4 to 6 days, upper lower or push pull legs lets you split 15 to 20 sets per muscle across the week so no single session runs 90 plus minutes. This keeps quality high late in a workout.
A muscle grows on roughly 10 to 20 hard sets per week regardless of template. Pick the split you will actually show up for, since consistency beats the theoretically optimal plan you skip.
Full body wins if you train 3 days a week; a split makes more sense once you can commit to 4 or more sessions.