It is a football match, bro. Even if a team can dominate the match, it doesn't always guarantee to win. Newcastle has done everything, they really dominated the match. But they are unlucky, they can't score more goals although they have more players in the field since minute 28'. Liverpool never give up, they could score 2 goals toward the end of the match. Newcastle must forget this, they must focus on the next matches. It is still the early of the season, there will be many opportunities to improve their position on the table.
If Newcastle don't give up and keep playing their football, then the results will come. Yet Manchester City and Liverpool are not ordinary clubs and losing to them with a minimum score is quite acceptable. You may not be lucky in some cases, but still the advantage in the game will still bear fruit later. And bad luck in some cases may well be converted later into luck in other cases. The championship has just begun, everything is ahead and everything can be corrected in your favor.