One might also note that many companies are no longer straightforward "one share one vote". They often now have voting shares and non-voting shares.
Thus some of them might own a modest proportion of the total shares, but it turns out they own a much greater proportion of the voting shares. For instance, I think Zuckerberg owns a minority of Meta shares, but is effectively unremovable because he owns over 50% of the voting shares.
Musk controls only something like 15% of Tesla votes, although I believe another ~5% are held by close associates. After that, Tesla has a rule that would make removing him require a two-thirds vote. But if Musk controls 20% of the shares, that means the 67% is only likely to come from the remaining 80%. Or in other words, over 80% of external shareholders need to remove him. That's a huge proportion in voting terms: just imagine how unlikely it would be to pass a referendum with that sort of pass rate.
As a judge recently noted, the Tesla board is also heavily compromised - it's full of Musk's associates and cronies. The lack of independence of the board was why the judge rejected a pay packet a year or two back. The shareholders have the votes, but the board still has a substantial amount of power, and Musk can exert additional control of Tesla through that.
