For increasing strength, the goal should be set on high intensity instead of too much stamina.
Split your training plan to increase strength in training days with a maximum of 2 muscle groups and ensure that adequate rest periods follow to allow the body to recover from the intensity of the workout.
An increase in strength is usually the effect of training with heavy to max. weights. Especially in high performance sports, a power increase is often sought after and there the emphasis is placed. There are many disciplines in which alone the power factor along with the correct technique plays an important role like in powerlifting, lifting, stemming, snatching and many disciplines of athletics. These include for example 100m sprint, clean and jerk, hammer throw, discus, javelin, etc. Many of these athletes also spend a large part of their time in the fitness center.
There is also great benefit of strength for bodybuilders. They can handle more weight and the muscles have stronger incentives for growth.