Evidently, because when I played it was really bad to give someone the baseline. Not any more?? Also, reaction time on help defense and or 3 point shooting is very lacking from most teams as well.
The game has changed and continues to change. Most teams have 3-4 guys on the floor at one time who can make 3's, and many times all 5 guys. Look at the great Iowa teams of 1987 with Marble, Armstrong, Horton, et all. Iowa running the Flex offense with the defense collapsed entirely into the lane. Everything more congested, much easier to be in position to help and guard when the defense doesn't have to spread out all the way to the 3-point line. And the 45-second shot clock slowed the game down dramatically, allowing teams to hold the ball.
On that Iowa team, Armstrong or whoever the PG in the game was the only one who would really handle the ball. Can't play the game that way today.
As to your point about not allowing baseline. It depends on how defense is taught by that coach. Traditionally, yes, teams didn't want to allow the baseline drive because the help was toward the middle. In today's game, if you let a guy into the middle of the lane it's devastating to the defense. From the middle of the lane, the player can shoot the short shot or can pass to any position on the court to open 3-point shooters. Forcing baseline allows the defender to use the baseline as a defender and as long as the defender does not give up an uncontested layup or dunk, it's preferred to forcing them to the middle.
I'm an old fogey, but the game and the people playing it continue to change, which is not unusual and it's expected. Opening up the floor and allowing offenses to move and to shoot is good.