Yes of course, the Queen has served for almost 70 years and Meghan has left after 20 months. It's impossible to compare a situation where one looks at 70 years of history vs the immediate present. Often we can't even tell what's happening right now and it's only upon later reflection that we understand the significance of events.
If in a future parallel universe, Meghan remained in the royal family until she was in her nineties, who knows how things could have panned out? No one knows. Could anyone have predicted that Princess Elizabeth would go on to become the longest serving monarch in British history and probably the most successful to have ever reigned? I don't know.
But what I do know is that there is going to be one heck of vacuum left when the Queen passes away and I think that everyone in the royal family needs to be ready for an enormous test. For almost everyone alive today, no one else has known any other monarch aside from the Queen and the transition is not going to be simple.