We just slept with our son in bed and didn't have a fraction of the problems in this department.
Our oldest child wouldn't sleep until we got him not only out of the bed but the bassinet all the way out of the room.
Our second child slept like a baby pretty much whenever.
Our third did fine in the bassinet, but now that she's older and transferred to the nursery she wakes up if even the slightest bit of light comes in through her door.
Kids are wildly different from one another from a very young age. I wouldn't assume that your cosleeping is the cause of your having fewer sleep troubles. If anything it might be the reverse.
But yes, in hindsight I would probably try some form of co-sleeping, even though everyone around us was advising against it(too much of a risk).
It turns out that co-sleeping is a risky thing if you are on drugs or are drunk.
If you are 100% sober, then it's perfectly fine. If you are high, or have had a drink, or are on some sort of flu medication (NyQuil, then the risks start ratcheting up.
So, since we're most worried about the parents that do drugs and drink around their infants, the common advice is to no co-sleep. It makes sense, I totally agree with that tack, but if you are willing to be 100% sober of all drugs and alcohol, then try co-sleeping and see how it goes.
Finally realized that I was going to fall asleep somewhere and did the same research. Co-sleeping sober ( and with a healthy BMI ) is safe and often better than sleeping somewhere else. We don't all have the money and space for cutesy recliners.
Second child did like to sleep in the bed and still does, though now we are trying to break the habit.
Each child is different and even one child can change a lot through different developmental stages.