You're 85 percent of the way there with 2FA and a credit freezes and the monitoring.
The SSA lets you set up an online account. It's a good idea to do this before some tries to do it in your name—that scenario is probably unlikely unless you're close to retirement. You definitely want to get an IRS pin so no one tries to file for a tax refund before you do.
Talk to your doctor's office about adding a note to your and your family's medical records that they have to call you before faxing your records to someone claiming to be a doctor bearing an official looking form.
You can add fraud alerts to the 3 credit bureaus so creditors are supposed to call you before they issue credit in your name. Useful if someone tries to unlock your credit with your PII.
You should add a freeze/fraud alert to your NCTUE report. They deal with utilities and cell carriers pull from them. There was a scam going on with Verizon for while where people would sign up for a contract, get 4 "free" unlocked phones and disappear.
If you want, you can also add fraud alerts and freezes to your Innovis (a smaller credit rating agency) report, and your Chex system (basically a credit report for banking) report, and freeze your LexisNexus (background stuff mostly for insurance) and Work Number (salary info) reports.
Many states allow you to suppress your public voting records like your address and phone number. That's where a lot of those data brokers first get your address.
Your phone carrier probably lets you set up a pin to prevent sim swapping. And you might be able to opt-out of them selling some info to advertisers.
If you find out your identity was stolen, you can file a police report, send that to the creditor saying to close the account, and include that with a letter to the credit rating agency to get it removed from your record. At that point you can probably get a new drivers license number.