Had a Bangkok to Copenhagen trip and it turned into a mess after Qatar canceled our original flight a few days before.
Spent hours trying to even reach support. When we finally got rerouted, it was this long chain: Bangkok → Muscat → Milan → Copenhagen.
Of course it fell apart. Delay into Milan meant we missed the last leg, got rebooked again, woken up in the middle of the night with new flights, and ended up arriving over a day late.
At that point we just gave up and bought our own tickets to get home.
Honestly the flights themselves were fine, but the support side was brutal. Felt completely on our own the whole time.