I read about Vattastic cease to exist in 2025, but now in august 2026, it still up and running ! Is it still reliable to use with Vatsim ?

I don‘t know. I would simply check and compare with vatsim-radar. If it still works good 🙂

agreed

https://vatsim-radar.com/

fantastic the amount of effort they have put into it. even now shows pictures of the aircraft.