I get what you mean, I've been on the receiving end of a tax bill that was 10x my actual bill. Indeed I had to pay first, then object, then get my money (without interest) back. It sucks, particularly as I really couldn't miss that money at the time, I actually paid them with debt and paid back my debt once they fixed it.
But perhaps you may already see why gold doesn't change that equation much. After all, take my experience as an example, I didn't have money to pay them, nor did I have credit on my bank balance (I didn't borrow through there). So there was no way for them to actually seize my money from my bank. A bit like having gold and withholding it, they can't seize anything from me, is this a solution?
No. After all, I was completely fucked if I didn't pay. Interest incurs on taxes due (quite a steep rate at that), plus penalties accrue on non-payment (super steep). In addition, at some point you get issues with the justice system. If then it appears you were withholding some gold, you're completely fucked. Now you're paying extra penalties for tax avoidance, which may be criminal depending on the magnitude. You say it requires physical force as if that's some kind of benefit, no way, you're life is screwed when it comes to that. You'll be heavily fined, may get jail time and may have a criminal record, as well as extra scrutiny on your taxes for the rest of your life.
If the government uses force on you by seizing your assets, the solution is not to hide those assets, e.g. in anonymous gold. You can't escape government force, and you're still liable for what you owe. They'll seize other assets you may have, like your home or car, or they lock you up. A system that lets you hide your wealth is not a solution, instead of them seizing your wealth they screw your life in a worse way and accrue penalties that total more than the amount due in the first place. At the end of the road you still owe what they wanted to seize.
The solution is different political policy, more legal protection for citizens to resist undue seizure, fewer mistakes with taxes etc. That, by the way, could happen when all transactions are digital, transparent, and more easily accounted for and reviewed. Even the most modern tax authorities tend to run most calculations on historical data, then give you a chance to correct them once a year. Obviously this is a flawed system: historical data is not accurate (e.g. you lose your job, they send a tax bill on the basis of your old income, you have no money, no taxes due, you must pay a huge bill, then fight it and get the money back. It sucks). And ordinary people have trouble with proper bookkeeping and do not give an accurate account of their finances once a year, it's really hard. In a world where finances are completely digital, this whole story becomes much easier and more accurate. It's far from perfect, but it's an improvement. Combined with citizen protections, a digital banking system can be beneficial.
Privacy and political oppression are enemies of financial transparency and digital systems, there are great arguments to make there against digitisation of banking. But asset seizing that you mentioned, I don't think is one of them, hiding wealth does nothing to solve the problem. That doesn't mean I approve of automatic seizing, by the way, no way. But the solution isn't hiding, it's different procedures, e.g. building in recourse prior to payment being required let alone assets being seized.