I'm pretty positive my parents haven't grout sealed their shower since they bought their house, so it's been at least, oh..... 27 years for them?
I mean, not that I recommend going this long, as now as their dutiful and caring adult child I'll likely be the one taking it upon myself to completely regrout the whole thing, but goes to show how long you could go with things probably being mostly okay.
What kinds of "various" admin level tasks are we talking about here?
A lot of desktop distros do have these kinds of tools in place. You can create and edit users and groups, set file permissions, create folders and files, download and update packages on your system, view disk usage, etc, etc. Shoot, specialized distros like gparted can be used to partition disks, or live boot a system to repair it.
But for a lot of things, building a GUI for the interface just takes so dang long to do, and takes so much more time and effort to get right than building out text commands, that it just really doesn't make sense to make it as big of a focus.
I bet you could do it if your instance didn't pull in a lot of traffic.
If it did..... I reckon that you might be able to pull it off to a certain extent so long as your internet package was good enough, but if you got hit with a Reddit-level flood of incoming users, your network almost certainly wouldn't be able to keep up.
Even if it could, if you were consistently eating through all the upload bandwidth, I reckon you'd draw the eyes of your ISP and they might send you a letter kindly and respectfully telling you that if you don't upgrade to a commercial line they're not renewing your contract.
Anytime you have to do significant demolition work involving an older home, if you are even remotely unsure of whether there are asbestos or lead paint in any of the building materials.
Or if you are doing demolition work on concrete in a closed location.
I reckon it'd depend significantly on the instance. Beehaw has a signup form reviewed by humans - measures like this are by no means perfect, but coupled with other bot detection software could help. If an instance developed a real issue with bots, other more strict instances could potentially ban up votes and comments from accounts on it.
At the very least, tracking instances that account interaction came from should be quite doable, so users part of more strict instances could filter out upvotes and comments from less strict instances if desired.