@Kyriakos: indeed.
If one sees the aftermath, everything would have been better kf dany hadn't heard on Jon in the beginning of season 7, if she just had marched on kings landing directly.
- kings landing burnt down like it is now.
- all dragons alive
- dothraki and unsullied full strength
- friends alive.
- night king still north of the wall, because no dragon to meld the wall.
Simple as that, Jon is to blame.... Just don't listen to the advice of someone who knows nothing.