I don’t understand why they are still in place

The US is explicit about this: "every possible means should be undertaken promptly to weaken the economic life of Cuba. If such a policy is adopted, it should be the result of a positive decision which would call forth a line of action which, while as adroit and inconspicuous as possible, makes the greatest inroads in denying money and supplies to Cuba, to decrease monetary and real wages, to bring about hunger, desperation and overthrow of government"

I don't believe the USA is buddies with Russia, though, they have opposing geopolitical interests. The fact that the USA is pulling out of Ukraine now is not because they're buddies with Russia, but because Ukraine is a broken toy now that the EU has fully antagonized Russia as a consequence of the invasion and has subserved itself to NATO and agreed to the 5% military expenditure (mostly to buy weapons from the USA military-industrial complex)