Why is Berlin's metro system so dysfunctional?

Over the past couple of weeks, I've experienced track disruptions on both the S-Bahn and U-Bahn. There were track works on the Ringbahn which also cancelled and delayed services, and the S2 and S8 soon after. At the same time, a segment of the U7 was also out of operation. Two sides of the U6 are currently out of operation and at the start of the week, it experienced delays due to a police operation. Even the M29 bus suffered a disruption at Kochstraße due to roadworks.

I can understand if this happens every so often, but it seems like there are bus, tram, U-Bahn or S-Bahn building works literally at any given time; which is very atypical even for other cities whose infrastructure is as developed (or more) than Berlin. Why does this happen all the time? Are construction companies constantly bidding to secure government contracts or something?

I'm not another ungrateful Ausländer who's picking on every minute aspect about Berlin to complain about. I'll admit that public transport is something Berlin can beat my hometown in, if mainly because they're more dependent on cars there.