Inter won Serie A last season with a whopping 19 points advantage over AC Milan and made it to the round of 16 in the Chamions League (unexpectedly losing to Atletico on penalties), but bookies don't give them much chances of winning:

Man City very rarely loses at home, so 1 point is probably the most that Inter can hope for.
Manchester City are stronger than Inter Milan but they are not too different in quality and competitiveness. Manchester City can lose this match and Inter Milan fans are given an amazing odds for their bets in this match. As fans of Inter Milan, they will have no issue to take the amazing given odds to support their team, watch the match either on television or on field while have opportunities to win big if Inter Milan get a good result at the end.
If you look at the quality, the English Premier League has a quality above the Italian League and I think it is very reasonable if the bookies give Man City a greater chance of winning because Inter Milan will play away in this match so it is not easy for them to beat Manchester City who are in their best form, although surprises are still possible but getting a draw might be a fair result for both of them who look equally strong.
I find it a little difficult to determine predictions when it comes to top clubs when they meet, especially since it is still early in the season so we don't know their full performance in this Champions League even though we can also analyze through domestic league matches.