I'll try to bullet point any relevant details

• Checked Tui's own tracking app on way to airport and plane was showing on time.
• Queued at checkin for 30 mins and was informed flight was 3 hours delayed
• Checked app and it now said 3 hours late so somehow in 30 mins they had realised it was 3 hours late. And now due at 02:04 (poor)
• Watched the info screen and at around midnight it said go to gate 25 as we will be boarding at 00:30
• Get to the gate but its the Dublin flight that is boarding so seemed apparent we wouldn't be boarding at the same time.
• 02:00 someone turns up and guides us onto busses that take us to the plane out on the tarmac.
• The plane is still being refuelled and cleaned for turn around.
• Loaded onto plane and informed of 3.5 hour flight. Some 45 mins shorter than expected
• Around 3h15mins into the flight we are told we will not be going to Manchester but that we have to stop in London Gatwick as the pilots have reached their flight time.
• We spend another 2.5 hours on the plane before they get busses to take us to the terminal. In this time they inform us that we will be getting coaches the rest of the way.
• 1.5 hours at immigration, 0.5 hours looking for unlisted baggage and 1 hour later queuing for coaches and we are on our way home.

I have approached tui and asked for proof that the journey was possible and that they didn't just put us through all that to protect their own pockets. So yeah, it might just have turned out to be an unavoidable situation, they have offered everyone the 400€ compensation so that we didn't have to go to the trouble of claiming ourselves and the crew were as occomodating as they could be but that is all only valid if they didn't create the horrible situation to save money on providing accommodation if they had cancelled the flight in Tenerife. Does it not seem odd to anyone else that they said they could get us there at a speed that is faster than the planes cruise speed so would have required a strong/constant tail wind for the whole journey but then have to drop us at one of the lowest geographical airports in the country?