Invest in BlackRock, your money is used to buy up stocks and bonds. In fact, buy shares in an iShares ETF and you're part of the famous BlackRock cabal.
BlackRock has been controversial for many legitimate reasons as well, but in recent years the biggest one has been ESG efforts ("environmental, social and corporate governance"), due to which they're now referred to as.... woke??? Several states stopped doing business with them because of their advocacy against fossil fuels. Florida pulled 2 billion invested with them because of ESG. Also, apparently they're all Jews and caused COVID.
The legitimate reasons for which they're controversial include the fact that their funds own large shares in literally everything. See healthy competition among publicly traded companies in the US by some miracle? BlackRock still owns a large percent of all of them. Or rather, BlackRock funds do. Again, these are mainly ETFs (exchange-traded funds), anyone can buy into them and own a piece of those pies. BlackRock owns things fairly passively.
Blackstone is different. They also have diverse investments from insurance to entertainment where they usually invest directly in companies, but they're controversial for their real estate investments. They own tens of thousands of single family homes and apartments in the US and during COVID made news for buying SFHs above market value so they could buy up entire neighborhoods to ensure people couldn't buy homes in those neighborhoods and would have to rent from them. They have a bunch of commercial real estate too, but that's not as controversial, since it's not actively removing homes from the market. If you travel at all, you're essentially guaranteed to have stayed at some Blackstone owned hotel at one point or another.
Ah and extra fun fact: While BlackRock is the bigger company these days, it's actually a former subsidiary of Blackstone.
TL;DR: BlackRock owns a bit of everything, or rather profits from everything from holdings that their customers own through their funds. Blackstone actively buys up shit you need to live.