Minimum technical knowledge indeed. Just not in the direction you are saying.
Bitcoin is not a repo. It’s a protocol, like TCP / UDP. You are probably thinking of the Bitcoin core client. It can be written in Node or Python if you want.
I’ve read the whitepaper, all the source code for Core, and built lightning mainnet applications.
Re: 51% attacks, yes they have happened, but as I noted above, the expense of running them is more than the gains. Because of PoW.
Re: real-world applications: Africa and other unbanked areas use BTC regularly. Citizens of countries with high inflation too.
Re: destroying the planet: many of the successful Bitcoin miners run on excess energy that would otherwise be wasted. Nuclear / hydro plants have excess energy as they generally online large portions at a time, more than is needed for a specific time. You can think of Bitcoin mining as bringing forward the ROI on a new power plant before it reaches capacity.