Being in multiple Lodges naturally depends upon how much time and money you can afford to spend on the Craft. Often it's something for later in life, when you're no longer so busy with kids and work and so on.
Of course some GLs don't allow multiple membership, in which case the issue doesn't arise.
Here in England, it's pretty common to be in more than one Lodge: among Brethren who are actively involved, it's probably a majority who'll be in at least two Lodges. We have around 220,000 subscribing members, of whom about half are lightly-involved or rarely-seen, but the other half are usually in a second Lodge so that the total number of memberships is over 300,000.
Some who are particularly heavily-involved are in more than two. I'm in six, but that's pretty unusual even here.
One I joined as part of a rescue team for a failing Lodge. One I joined because it has outstandingly excellent standards of ritual. One I joined because it's a special-interest Lodge for those who follow a particular sport. One I joined because it's closely connected to a masonic teaching body with which I'm heavily involved. One I joined for its history. One I joined because it's in a foreign country which I frequently visit.
T & F,
Huw