there's two sides to that coin:

  1. Jailbreaks are harder to come by these days as the OS has gotten significantly more secure
  2. Apple added most of the reasons for jailbreaking to iOS directly, making the motivation small

The only I reason I did it back in the day was to unlock my iPhone 3GS, this being before Apple and AT&T offered the capability. Because I used a modified iPad bootloader to do it, it made my phone painful to upgrade for almost two years.