You're talking about Hinduism. Buddha thought that the Indian caste system was bullshit and that Brahmins were full of shit for claiming they were inherently superior to everyone. He also would have been against things like crushing yourself under a statue as delusional and a source of negative karma for both harming yourself and for the terrible state of mind you'd be in at death, which is a major factor in what you reincarnate as next.
Buddhism is generally lot more sensible than Hinduism and was even directly opposed to it. Buddhism's main issue is just that is easily comes across as overly nihilistic since the main conceit of why you would want to achieve Nirvana is basically that all the suffering in life outweighs the pleasure so you should extinguish your ego and subsume your sense of self to the cosmos to be forever free of suffering.
Notably, the mainstream school of Buddhism in Japan feels kind of diet Buddhism and it's basically all about how enlightenment is impossible on your own and you shouldn't try, and instead you should just trust Amida Buddha's (Amitabha's) vow to save everyone and if you do you'll automatically reincarnate into a state of Nirvana in Buddhist heaven and then eternally reincarnate as Buddha spirits to help those on Earth. The second most popular strain in Japanese, Zen Buddhism, doesn't even believe in escaping reincarnation at all, and instead thinks Nirvana is just reality itself viewed through enlightenment from a lack of ego and attachment.
