Mbappe goal against Spain.

Was this offside.

Yes for me if the official raises his flag immediately the ball is played.
Go back awhile to the Liverpool one where the guy was miles offside.

This needs some serious looking into.

Yes this was offside.
Apparently, the ref explained it by saying that new phase was formed?. WTF? Is this football or rugby?

Not sure whether you saw the enlarged replay, but the defender Eric Garcia DID touch and marginally deflect the ball. My opinion, even under the old rules, this goal would have stood because of the defender "touching" the ball.

Two scenarios :-

In play the striker is lazily walking back into his own half, and a team mate plays the ball over the last defender, if the striker picks up the ball and goes on to score, that is offside - no dispute. Conversely, the same striker lets the ball run to the opposition keeper, why should the linesman flag him offside when he has made no attempt at intercepting the ball?

Scenario (2), the same lazy striker is walking back into his own half, and the defender, without realising the striker is between him and his keeper and executes a back pass, unfortunately to the striker, who takes the ball and scores. How is this any different when the defender got the last touch?

For me, it's not like he was in an offside position and was obstruction the view of the keeper on a goal bound shot from a team mate.

If you can, watch the enlarged replay, officials got it right in my opinion, not that i had a bet on the game.