Mainly because some extensions stop working after each update. I mainly moved to Gnome because it does have a better password and key system, as one of my apps doesn't work with kwallet. But seahorse still works with Plasma, and I make sure that kwallet doesn't interfer.
I tend to switch back and forth between Ubuntu and Fedora, although it's been Ubuntu the last few years. And I always use the Cinnamon desktop which is based on Gnome 2.0. Installing a system first and then switching to Cinnamon desktop leaves the Gnome desktop installed and this has caused me issues in the past, for a long while that's why I preferred Fedora, I could install a version that came with Cinnamon instead of Gnome. Now Ubuntu does that too.
Throughout the years I have never understood the point of kWallet or Gnome Keyring, to me they seem more like a security problem than a solution. All your passwords stored in one place - handy.
Over the years I've only had a couple of programs that complain about wanting Gnome Keyring, and the absolute worst of these is Google Chrome. If I want to join meetings with people using Microsoft Teams then Chrome is the only available Linux option.
I always hated Chrome right from it's very inception, reminds me of the old Opera web browser which was always crap. Then there's the complete lack of trust in Google regarding security and privacy, needless to say that I hate Chrome with real passion and see it as a sometimes necessary evil.
But every time I open Chrome it wants my root password so it can access Gnome Keyring, which I have never in my life used. Trust Google with my root password? Like hell! Why does it require access to my (nonexistent) password list to browse the internet? In me this triggers all sorts of alarms about trust and security and has further increased my distrust of Google.
When I open Chrome it presents that pop up box asking for access to Gnome Keyring and I just treat it exactly the same as I used to treat that "access denied" message in windows - click it off and try again, it only asks 3 times and then it lets you do whatever you want without permissions granted.
Yes - there's a windows hack most of you don't know about - Windows only denies access 3 times then lets you do what you want regardless of permissions. The term Microsoft Security is an oxymoron.