I agree with much of what you say. However I do believe that he is acting in an unaccountable way. The problem is that the system doesn't make him accountable now, and his power (through patronage) is so large that the normal checks and balances that should prevent an abuse between the 'public accountability - every four years' have failed. Congress should be stopping him breaking the law. Where are they?
Regarding the 'company' matter. I totally agree that an inefficient public sector is sub-optimal - though less sub-optimal than for a company. And it is always wise to spend public money well. The issue I find is two-fold:
Firstly, the public sector has a moral duty to serve all the population - which necessarily makes it less efficient. The current approach from Trump and Musk has lost this key moral underpinning. If (as an example) you have to provide services to the 50% of people who are below average, then it requires that the services have lots of 'help' and 'cost' to allow these people to access the services. Even if they look 'inefficient'.
And I believe the US is rich enough to aspire to not have people starving (and homeless). Everyone can be dealt a bad hand, either at birth or during life.
And it isn't inefficient to prevent pandemics, or hold companies to account, or have internal audit within government itself.
Secondly, there is the 'externalities' issue. Musk just fires people on the lower end of the bell-curve in his companies. However in a country, this doesn't work. There isn't an outside void into which to cast people. Ultimately the country picks up the pieces or people starve (see the moral point above).
That, for me, is the key difference. A company RELIES on the state to provide the 'diaper'. And a company RELIES on the state to just absorbe all the trash that a company creates; unemployed people, environmental mess etc. Its not companies that pick up the pieces. Its the State that underwrites all of this.
For me this is the key difference between a Company and a Country. A country has responsibilities that transcend a political term and cover the whole of the population and a physical space.
People hand that responsibility to a State because it requires collaboration and co-ordination at a level no individual can achieve.
Companies wilfully ignore any responsibility not laid out in Law. A country picks up all the mess outside that.
But once a State begins to deny its basic responsibilities towards its population - what then? Do the population owe a duty of loyalty to it any more?
As an example, one of the basic responsibilities is to follow the law.