Are Steinitz's rules still good?

The first world champion was Wilhelm Steinitz. He proposed the following rules more than 100 years ago. Are they all still valid after a hundred years? Are they actually laws of chess that cannot be broken without unfavorable consequences?

1. At the beginning of the game, Black and White are equal.

2. The game will stay equal with correct play on both sides.

3. You can only win by your opponent's mistake.

4. Any attack launched in an equal position will not succeed, and the attacker will suffer.

5. You should not attack until an advantage is obtained.

6. When equal, do not seek to attack, but instead, try to secure an advantage.

7. Once you have an advantage, attack or you will lose it.

What do you think? What do the experts say?