What is wrong with our bus system

I get off work at 4:30, and the bus is supposed to be every 15 minutes. The bus is scheduled to be at my work at 4:36 and every day it is there at about 4:54, then the next bus that’s supposed to be 15 mins apart from that one pulls up behind it at 4:56. I have absolutely no idea why, but it happens every single day.

Then, I get to where I need to transfer and the bus I need is already gone, so I wait another 20+ mins for that one. I live a 9 minute drive from my workplace and it takes me on average 80 minutes to get home on the bus. I don’t get it.