The key to making physical changes with your training program (ie: improving your physique, building muscle, etc) is PROGRESSION. Most people think that means lifting more weight than you did before, which certainly is the primary way to progressively introduce greater muscle tension. But if your goal is to gain muscle or improve your physique (rather than just to “get stronger” or improve performance) there are other forms of progression worth implementing.
If you’re new to lifting weights then it makes sense to focus on getting stronger first. But if you already have at least a year of lifting experience and a decent strength base, it’s time to look at ways to progress in addition to increasing load.