While the difficulty of achieving single logout (SLO) is interesting technically, we can zoom out a bit and see that SLO died because all web logout processes a

While the difficulty of achieving single logout (SLO) is interesting technically, we can zoom out a bit and see that SLO died because all web logout processes are pointless given how screen lock and user switching have become ubiquitous. It hasn't always been the case, but it is now. If you're letting someone use your OS session, they can auto-fill passwords from your password manager, maybe install a keylogger, who knows what else. You must lock your OS session, at which point you can keep web sessions logged in.