The Glorious Revolution wasn't a revolution as such; it was an invasion by a foreign army - just not one that met military resistance. You could as well describe the invasion of Norway by the Nazis as a 'revolution'.
The British system of government is about ninety years older than that of the USA - after the English Civil War, Restoration, and the 'Glorious Revolution', the system was basically established in its current form. Sure, there were some adjustments, but then, the same is true of the US system of government. If the amendments to the US constitution since the late 18th century don't count as sufficient to change the 'system', then nor do the similarly minor changes to the British 'system' since 1688. If they do count as sufficient, then the US system has only been in place at most since the 26th Amendment was ratified in 1971.
So the idea that the US has the oldest 'System of government' bar Iceland's is highly questionable; the British certainly have at least as strong a claim to having a system that is fifty percent older than that of the US.
To the OP, whether a revolution improves things depends entirely on who you ask. The Russian Revolution of 1917 certainly improved the lot of most Russians; life under Bolshevism was no picnic, but it wasn't worse than serfdom under the Tsars, at least for the majority of the population. Of course, that large minority who had the misfortune to be starved in Stalin's collectivisation famines wouldn't agree.
Revolutions rarely lift the oppressed very far - but they often lift them a little, and a little makes a big difference for a lot of people.
The 'important' people - those who had wealth, power or stature before the revolution, almost always end up worse off, and most reportage focuses on them, so it's easy to get the impression that revolutions have always made things worse, but that's far from a universal truth.