First of all, it was only the last world cup, which was decided by a penalty shootout. In 2002 Germany was overmatched and lost 0:2 in regular time against Brazil.
Penalty kicks might not be the best way, but everybody is used to it. Van Gaals suggestion with removing players might be interesting on first site and might even work, but many people would oppose such a change because it completely changes the game since a 7on7 or 8on8 is way different from a 11on11 soccer match.
This solution should favor teams with great technical skills like Brazil and would put defensive minded teams, whose strength is shortening spaces for opposing teams, in a disadvantage. The game would somehow be moved into the direction of beach soccer so to speak.
If you don't have a problem with time constraints, you could let them play 11on11 until someone scores: Yes, players would get tired, but stamina is a big part in soccer anyway and teams who get tired would have to do more running in practice, so that they are fit enough to play 140-150min or longer.
But this might not be the way, TV wants to go ;-)
And honestly, I would miss penalty shootouts: No more teasing of England (Southgate, Beckham...) and other countries, who just can't win a shootout
(Although I had a hard time back in 2000, when the Dutch dominated Italy and were eliminated because of missing 5(?) penalty kicks...)
And I also would doubt, that most RXers convert 70% of their penalty kicks against a world cup goalie.