My state of residence restricts access to certain sites. It’s all bullshit.
Anyway… The ISP is either a common carrier or a content provider. Pick a fucking lane. You can’t have half and half. Either you are responsible for ALL content provided or NONE.
If you choose none then you MUST NOT restrict access to any content.
If you chose ALL then you may restrict content based on what you are willing to take responsibility for. But in that case if someone does something illegal with content you provided you are liable.