I wonder how much in houses is related to how frequently we re-furnish our houses compared to 50 years back. I know old people who have the same wallpaper and furniture that they had when they got married, "if it aint broke, don't fix it", the younger generation is now much more likely to.
I have had 3 different sets of sofas/chairs in the last, perhaps, 7 years. Neutral colours means I can change the fittings to whatever I feel like. What I don't want to do is repaint everything to match.
I do think this is part of it. When I got married my spouse wanted a set of really bright-colored dishes. I liked them too, but was worried we'd get tired of them and want something else, and preferred neutral colors for that reason.
Neutral colors aren't as appealing to me at some level but I'm also less likely to tire of them, and as you say, I think they're more compatible with other changes.
I've wrestled with this in some recent remodeling too, thinking a blue would be nice here, but decided against it because I didn't want to change my mind later. But I was remodeling, so maybe it's inevitable anyway.
I think so much is disposable in our lives that maybe we gravitate toward colors that seem less ephemeral.
For what it's worth, I have never once regretted making a bold color choice in my home. I've been using bright orange as a the primary accent color in my kitchen for about fifteen years across four homes and still love it.
Life is too short for fucking beige. Build a space that reflects what you love and if what you love changes, so be it, change your space then. But there's no reason to shortchange yourself now in subservience to a future self you may never become.
I personally bought a white phone once, it was the S10+, i did it because it was the flashy color and it was on every AD, also the Black sucked on that phone, there was no midnight black.
After a couple of months, I regreted it, and my next phone was naturally black.
I find with things like "plates" that the normal china/white/off-gray colors are fine.
But with things like mixing bowls, measuring cups, etc, having bright colors is incredibly helpful if someone is in the kitchen with you - "give me the red cup" is easier to understand than "give me the 1-1/4 cup, no that other one over there".
I'm no interior designer, but I think it's fun to let decor mutate slowly instead of "redoing the living room". If I see a chair I like, what do I need to change for it to fit in with what I have? I don't know if it's cheaper in the long run, but it does keep things more interesting imo.
I have had 3 different sets of sofas/chairs in the last, perhaps, 7 years. Neutral colours means I can change the fittings to whatever I feel like. What I don't want to do is repaint everything to match.