Privateer - goal size is not a problem for a good side when they are playing a side they are completely superior to. The problem is when you have two evenly matched sides there is very little scoring - as a casual spectator this leads to several problems:
1. 0-0 draws are a bit boring!
2. If a side does score a goal they tend to go into a completely defensive mode to try to stop the other team scoring and don't take offensive risks - again leads to boring game to watch.
3. When you get to the end of extra time with a drawn match you go to the penalty shootout lottery which seems to me like a really stupid way to decide a sporting event at the World Cup level - may as well just toss a coin to decide the winner.

I would think that a modest increase in goal size (eg. extra 1m wide or 1/2m high, or both) would help to increase scoring opportunities.

Or maybe you prefer these ideas that my wife came up with after watching a match the other day:

Instead of policing the offside rule with video why not just get rid of it? That would certainly improve the scoring chances.

Also a rule used in some versions of indoor soccer - no passing backwards over the centre line.