> At some point if you're a rich-enough party you can just take over these networks with enough money and resources.
This is such a concern levied against cryptocurrency; why does no one levy the same concern against traditional publicly traded companies? That someone who is rich and powerful enough could simply take control of Apple, or Walmart (assuming they make >50% of their outstanding shares available for trade on the public markets, which some public companies do)?
The reality is: It is a concern. But its a vanishingly small one. To do so would be, in many cases, suicide; and it would be even more-so with cryptocurrencies. It would take an obscene amount of money and resources, converted into assets which held value under the societal context of the status quo. The status quo doesn't like changing; the assets would probably lose all their value as everyone in the 49% abandons their investment. What would this hostile takeover gain? A few billion in revenue? They'd lose far more in the attempt.
For most newer cryptocurrencies (not Bitcoin), this attack is not a matter of owning 51% of the mining power, but rather 51% of the currency itself (proof of stake). To do so, for any reasonably successful and valuable currency, would be crazy. Its just not a concern, period.
It may be worth elucidating this, but: bitcoin is on the way out. The crypto community has absolutely striated into two groups; the bitcoin traditionalists who build ten acre data centers next to volcanos to farm their digital gold, and those more forward thinking who are actually interested in solving the bigger, more tactile problems with cryptocurrency like real use cases, environmental impact, etc. So, many of the concerns surrounding bitcoin, which evolved in the '10s when it was the fastest growing player on the block, are simply no longer relevant.
