Quality is mediocre. The trains are often delayed, which is a problem with the size of the network and cascading failures. Once they do get to A, they get from A to B just fine, the seats are okay, the luggage space is okay, etc. The DB Navigator app is useful for finding alternative routes but it won't tell you whether your ticket is valid for them. It will tell you if the delay is so long that you're allowed to use any route.
The train is late. The lounges suck or are tied to a complex system of ticket tiers that seemingly don't correlate to price. You bought a specific seat but the train was changed so now no assigned seat and lol on a refund. And fuck you if you're crossing borders.
Germans travel a good amount by car for good reason [1]. When I'm in Germany, I tend to drive between cities because the alternative is burning several hours in buffers and delays.
[1] https://ec.europa.eu/eurostat/statistics-explained/index.php...
You have something mixed up there.