He leaves behind a Cuba that was embargoed by the US, their closest and largest trade partner after the US had staged a failed invasion to overthrow the government. This forced them into the Soviet sphere of influence for supplies and trade.
Then, when the Soviet Union collapsed at the end of the cold war, it could no longer support Cuba. The island nation was driven further into poverty and essential goods like food and medicine became scarce.
And what did the US do at that point? Did they reopen diplomatic relations and try to find some rapprochement after an era of high tensions? No. Instead they decided that now was an excellent time to extend their embargo to include food and medicine as well, which were up to that point exempt from the trade ban.
To point to a single man and his inner circle as the sole cause for the sad state Cuba is in today is just as absurd as to deny the wrongs of the Castro regime, nor did he only do bad things for the Cuban people. The "trope" of education and healthcare being available to all is not some straw man. It is a legitimate achievement, and one that many nations the world around have not been able to match, no matter their affluence.