The other day I walked up to a newsstand and asked the newsguy if he wanted to buy US$100 of Bitcoin. He said sure, checked the price, did some calculations on his cellphone, and proposed an amount including a commission for him. I agreed, scanned his QR code on my phone, and posted my transaction to the network. I walked to a nearby shopping mall to pee, and then saw that the transaction was confirmed. I walked back to the newsstand. He handed me a US$100 bill.
I didn't sign anything, make any appointments, buy any insurance, walk into any offices, present any identification, or even tell the guy my name. The total time involved was about 20 minutes, but only because I wasn't using Lightning. I had a similarly informal and short, but more argumentative, experience with the previous transaction, at a winery whose owner loudly insisted that he hadn't received the money... until he realized he was checking the wrong phone.
You are so full of shit comparing this to a real estate transaction that I am at a loss for words. You're about as full of shit as the winery guy. He, too, was blathering all sorts of nonsense at me about Bitcoin that showed he didn't have the faintest idea what he was talking about.
The scenario you're talking about is a 51% attack where big mining pools collude to ensure that nobody else can ever mine a block (because it might allow the laundering of tainted coins). That would be a global and extremely obvious disaster for the Bitcoin network, and it would be remedied by whatever measures were necessary to end the attack, possibly including a hard fork or strategic bombing.
Remember that the world's investor class now has 2 trillion dollars tied up in Bitcoin, and they do not want to see it collapse, and such a successful attack would greatly undercut investor confidence in the value of the asset. The Bitcoin crowd has enough pull that they extracted a pardon for Ross Ulbricht and got a friendly SEC head this year. Even before that, when one or another pool would grow to the point where it might be able to mount a 51% attack, it would get hit by DDoS attacks to bring it down.
You're comparing that to a bank declining a credit card transaction because you're in another city.
Governments have been pressuring Bitcoin miners for over 15 years; it's outright illegal in many countries. The hashrate dropped by more than half when the PRC outlawed Bitcoin mining. The effect on the functioning of the network has been pretty much undetectable.