Almost every organization I've worked with has the policy of "if you get malware, we wipe your whole machine and reinstall the gold image" which is quite disruptive because you then have to reconfigure your settings and reinstall all your software packages and regenerate SSH keys etc. It can be a whole day of downtime and then a week of slowly getting back up and running full speed.
But if your hardware and local software are irrelevant, you can just swap your dumb terminal for another dumb terminal without skipping a beat. And with things like Chromebooks or iPads (actual real dumb terminals) the likelihood of getting to a "wipe it and start over" goes down a lot compared to machines running a full-fledged OS with a privileged user account.
If you drop your Chromebook in a lake, you could run to Best Buy and get a new one for $300 and you've only lost an hour or so, and if all your data is stored in OneDrive and your IDE is Codespaces you haven't lost anything of real value.
For the individual: similar concerns of hardware failures losing work go away a bit (there are still ways to lose everything, but less of them), easy moving between environments (desktop, laptop, phone), ...
Though it depends how much is pushed to the "cloud". You may still need some meat on the local resource bones if not pushing any CPU crunching into the sky too.
Essentially we are reinventing the thin client from the 90s/00s, which in turn reinvented many mainframe concepts, not that either ever completely went away, with an eye on much the same benefits.