It's extremely common for people to go into a gym and lift heavy weights, completely neglecting form and tempo. Lifting weights 'any old how' will not give you the results you want, and you could easily get injured if your only goal is to 'lift as much as possible' and don't bother with correct form.
The best way to build muscle is to keep the working muscle under as much tension as possible. This is where form comes in. If your form isn't good, then you won't be working the desired muscle as much as you would like. However, if you focus on your form and tempo, you will be putting a lot more tension on the muscles. For example, during a bench press, you want to focus on the form of the move but also the speed of the lift. During the eccentric phase (lowering the bar) you want to control the movement, taking roughly 3-5 seconds to lower the bar. This will cause a lot more tension on your pecs - you won't be able to lift as heavy, but it is a lot better for building size and strength.
This kind of training is known as 'time under tension' or 'TUT'. I have personally incorporated it into my training, and I've noticed a difference. I can't lift as heavy as when I do a normal lift, but I can feel a lot more tension on my chest (during the bench press that is), and I have noticed a strength increase as well as a size increase.
Those 'egotistic lifters' out there might not like doing this, as they will have to lift less weight, but it does work and will give you far better gains.
If you research any top bodybuilders, I would guarantee that they don't just walk into the gym and try and lift as much as they can - they focus on form and tempo. There are plenty of youtube videos showing you time under tension training, so I advise you to check them out. Time under tension training can really take your game to the next level.
Lee Gregory Fitness