Erasing Stolen iPhone

Hello community,

I have already asked this question in the French portal, but since the matter is quite urgent and I still haven't gotten an answer there, I thought maybe the English-speaking members could help.

So basically my iPhone 13 got stolen last night. It still appears offline on iCloud and I haven't been able to locate it yet. I Have already contacted local authorities as well as marking it losr on iCloud (I received an email confirming that Apple Pay has been disabled on the phone).

I'm not that optimistic that the local authority will find it, so what I would like to do now is make sure that the thief can't use it, and more importantly, can't have access to my data and apps (banks, emails, ...). The phone is protected with faceID and a personal code, however, I would like to go a step further and make the phone completely unusable.

I saw on my icloud account that there is an option to erase the phone. If I choose to erase it, will the phone become completely unusable?

Thanks in advance for your feedback.