Owners of corporations often want democracies reformed into corporate autocracies so they can buy some or all of one. Past fascist regimes have favoured corporate states.
https://en.wikipedia.org/wiki/Italian_fascism#Corporatist_economics
I think you are right in that he seems to be investing in political parties, obviously expecting a quid pro quo.
The trouble is that his "investing" in Reform in unlikely to actually give him any significant influence in UK politics. I'm still unsure how much Reform impacted the last General Election as it can become difficult to separate out influences eg how much of Reform's vote gain was because many were unhappy with the Conservatives but couldn't bring themselves to vote Labour, only really leaving them Reform or abstain. It is reported that some "warm" to Farangé and some like that comes across as a "regular chap" more than a "politician" but did that make people want to vote for him rather than just give them an acceptable place to vote that wasn't Conservative? If the Conservatives even start to turn themselves around I suspect those votes lost to Reform might return - the electorate have short memories and Labour have enough majority to last 5 years.
So, with our First Past The Post electoral system if Musk is seeking influence then he's chosen a real long shot with Reform.
I wonder if he's just discovered a new game and one that develops his image in far-right political circles ... so he gives the impression "
he's now so powerful he's influencing politics across the world" and maybe people overlook that his last commercial aquisition is now work a fraction of what he paid for it.
Ian