For what it's worth, I agree with you.
After all, none of us living in "democracies" were ever given a chance to vote about the legitimacy of the constitution, of the law codes, of the armed thugs, of the state itself...
I don't know that a system with no government or voluntarily funded common services and functions would be "better" than what we have, but civil forfeiture is not fundamentally different than taxation, from the perspective that OP viewed it. The government decides that is a legal way to raise revenue and they carry it out under threat of force.
You can disagree with civil forfeiture while agreeing with taxation, but not with general complaints about a state sanctioned violent gang stealing from the populace.
I'm certainly no fan of civil forfeiture but I eould argue that it's fundamentally different from taxation.
Taxes are impersonal. The rules apply to "everyone" [1]. They are written up, voted on (by congress) and so on.
Civil forfeiture is a random event made by a random cop on a targeted individual. It is the very definition of unfair.
Equally you can define taxation as "stealing" hut it's really not. (CF is stealing in my book). It was different in the past, but today taxation is used to pay for things - it doesn't just go to the bank account of a person.
-some- govt and govt services are necessary for society to function. (A quick look at places without govt demonstrate that.) And yes, one can argue about the priority of one service over another. But fundamentally govt serves the society and taxes is just the way that gets paid for.
The scale, priorities, spending of govt is obviously up for debate, but funding it is necessary, and so I don't consider taxes to be theft.
Incidentally, if you feel that all govt is bad and we should exist without one I recommend trying to live in a place where the govt is non-functioning. Thats when you discover where all that spending goes and what it achieves.
[1] for some definition of "everyone" - the system has flaws.