My wife is Paulista, and we are going next month to see her family because it's been 2 years and we are taking precautions with regard to our health.
Statistically speaking, Sao Paulo is safer than many large American cities. However, Sao Paulo is an oasis. It's a first world city in a 3rd world country. My wife's family has a beach house in Peruibe and it's in a compound with 12 foot high walls with razor wire on top. You go through some serious poverty between Sao Paulo and Peruibe, with a few gleaming high rises mixed in. I would not get off the highway along this stretch unless it was life or death.
The last time we also went to the mountains, to Brazil's highest city Campos do Jordao, at 5300' elevation. Saw a lot of poverty then also, but not quite as bad as going from Sao Paulo to the coast. Still, we only stopped at one rest stop that was gleamingly new and filled with well dressed patrons.
Brazil is pretty sketchy but it can be fun, just stick to the places where there are other tourists, is the advice I'd give. Don't get off the beaten path like you might in the US. Getting lost on purpose is not a good idea.
[edit] and do not ever take a Favela tour as is popular for people to do now. Buses have been held up at gunpoint.