You had a little tax collector dude (or dudes) that went around knocking on doors and collecting a % their on-hand assets (which you set). You could exclude areas if they were too far away, or too dangerous. Your tax collector(s) could be ambushed, which frankly was the primary reason to build defenses.
And, you could tolerate some thievery so that you could occasionally extort money from the thieves guild in sort of an unofficial tax collection of unreported income.
All that in a fantasy game. It can be done.
I believe there's a modern revamp version for mobile: https://www.microsoft.com/en-us/p/majesty/9nblggh1850p
The voice acting was good, but they didn't have many sound bytes so it got pretty repetitive. Also whenever a gnome died they'd say "But I'm just a gnome...". When minotaurs were trampling your kingdom, it could get pretty annoying.
https://en.m.wikipedia.org/wiki/Perverse_incentive#The_origi...
[1] https://en.wikipedia.org/wiki/Farm_(revenue_leasing)