Bitcoin

they own the massive "mining" operations

This doesn't make them controlling Bitcoin at all. Bitcoin has a polycentric governance when no single actor could control it. Mining is a more complexe than simply buying ASICs and burning electricity. Wall Street guys invested millions if not billions into Bitcoin mining company that have died because it was just rich guys knowing nothing about mining that thought that they would make tons of money.

Also while you're right that currently they are more private companies you could have governement-mining like Buthan is doing right now and has done for a few years. Community mining could also exist, I mean a mining pool is a cooperative design.

You're describing the concept of a blockchain.

No. The blockchain is just the format use to store the data, the real innovation come from Nakamoto's consensus, and the difficulty adjustment.

Blockchain is a buzzword from the banking industry and fintech. Blockchains existed decades before Bitcoin but they weren't marketed as such. Even git (2005) works like a blockchain but with another governance and without all the decentralized BS.

Currency is the first application but we already have other uses such as OpenTimeStamp used during Guatemala's election of 2023 for exemple. And we will have more and more once client-side validation technologies such as the RGB protocole will be live for exemple.

Of course it has failed as a currency

It hasn't fail as a currency when you watch what is happening in some Africa countries such as Nigeria, Democratic Republic of Congo to name a few. Same for latin america with Peru or Asia with India or Vietnam.

Also the ammount in USD that is transacting on Bitcoin yearly is in par with other payment processor such as Visa, Mastercard and outrunning AmericanExpress.

Bitcoin will never replace state money even tho many bitcoiners idealize this. However there is a high probability that in the future many if not most or all of the state currencies will run on Bitcoin as it's more efficient. We are at the beggining it's like the 90s for the web when nobody thought that this useless technology will permit us to buy stuff online. But this is me speculating here.

but you still need to be certain that your computer is secure

Same for every single software... Banking, PayPal etc... are not immune to that.

You can also mitigate the risks proportionnaly to your wealth and threat model. Multi-device multisig is an exemple. Liana Wallet with miniscript and timelocked is another.

You don't have to be as secure for a few thousand sats, than tens of millions, than a full bitcoin or more.

We (human) are very bad at information security. Bitcoin had a strong impact on that field of IT, it is so big that in 10 years we have made enormous progress, significantly more than in the last 50 years of computer science.

It makes much more sense to have a handful of trusted entities

How does Bitcoin is incompatible with that vision ? Any way I disagree with that statement and I think that these "handful of trusted entities" will indead use Bitcoin to transact. But again this is my point of view and me speculating.

with ssl certificates

SSL certificate also use asymetrical cryptography just like Bitcoin. How is this different since you also have to be sure that the private key of the "trusted entity" isn't compromise ?