There is a lot of reading between the lines necessary because of the network of reporting from other Chinese that’s worldwide.
Note: those actual opinions are not necessarily “life is baaaad what a niiightmare”, they can be quite nuanced just like anywhere else. Something as simple as “I kind of liked that unsanctioned rendition of the Chinese national anthem” could have the same consequences for them and their family as a total denouncement of the Party.
Single party control, coupled with a constitution with articles that undermine all the other parts of the constitution, can really impact the experience to express anything.