Chelsea are an investment fund too, no?
Crucially, they have Boehly in charge though - not sure how much he put in but he's the head honcho. I didn't know anything about the guy but after this summer and a bit of reading, he's one of those Americans in it to win it and not profit off people's passion for a sport.
If we get another similar prospective owner, it'd be great but I am just pessimistic. He (or she or they) won't even have to spend as much money so quickly because United fans' expectations have been lowered so far we're willing and/or happy to wait.
The new people just need to hire the right people to run this institution and let it grow organically with a 10-year plan for a new stadium, winning the league in 5 and a great women's team.