Preferring bigger when getting older?

A few years ago my wife would sometimes struggle to fit all of me in certain positions. I'm only average sized, maybe a bit thicker than average. I put it down to her having a very tight pussy. Definitely the tightest I've ever been with.
Over the last year or so, I noticed her more accepting and definitely taking it harder than she normally would. I started trying bigger toys on her and after a small adjustment period, she now comfortably takes a 7x5.5in dildo. Her pussy actually reacts differently with it and it's gets wetter than I've ever seen with mine. She still tells me she prefers my cock though.
I've also noticed that she's not as tight as she used to be when we're fucking.

Has anyone else experienced this? Just wondering if maybe it's an age thing? I'm certainly not complaining, just curious 🙂