This ignores time dilation for the traveler.

After 70 days 18 hours and 10 minutes at 5g you reach 0.9999c, time dilation at that speed is over 70x. Which means what looks like 30 years for us at earth only takes 30years/70 = ~ 5 months +70 days (if we ignore the time dilation leading up to 0.9999c) for the traveller.

If you have a space ship that can accelerate at 5 g constantly, you can travel to the nearest black hole in lees than a year. In your reference frame