Red and Blue were the only two Pokémon games (in North America) that were not in colour. They were also the only games that preceded the hit TV show.
This gaming series has evolved a lot since the original release of Pokémon Red in 1996. The most recent release of Pokémon doesn’t include any of the original 150 at all. It's understandable. Otherwise the game might become too overwhelming, especially for the younger players that recently started to play Pokémon. This new generation of kids have their own generation of Pokémon, and we have long surpassed the time where catching all 150 Pokémon was a reasonable goal.
Even in the first games, catching all 150 was a challenge. There were the few Pokémon that would not evolve unless it was traded. That means this mission was futile if you did not have friends that played the game, or if none of your friends had a link cable, or if you just didn't have any friends.
Beyond catching all 150, there was also the challenge of figuring out type differences, picking your top 6 favourite Pokémon, training them the best way you possibly could, defeating Team Rocket and Giovanni, defeating the Elite Four, and overcoming your rival.
That is the path to become an original Pokémon master!