Will factory reset rid malware/spyware?

Most likely the only thing he gained is your email address. everything else is fluster/scam.

But yea resetting the phone via iTunes/finder wipes everything. and downloads new software from the servers.

Everything you have done will help to remove any residual data from your unfortunate excursion to an unwanted site.

As a precautionary measure to largely inhibit possibility of hijacking your browser, I strongly recommend that you install 1Blocker for Safari on your iPad/iPhone/Mac. Whilst it cannot prevent you from receiving unwanted email from extortionists, it will inhibit your browser from linking to many categories of unwanted sites and content. As such, without delving into the technicalities, exploits, such as the one you perhaps experienced, are far less likely to occur.

1Blocker is by far one of the very best content blockers ever released for iOS/iPadOS/MacOS. 1Blocker is highly configurable, but in its default modes is almost install and forget.

https://apps.apple.com/gb/app/1blocker-for-safari/id1365531024

1Blocker will also block access to “adult” material unless you entirely or selectively disable the blocking features for specified sites.

I hope you find this to be of some help - and might provide a suitable solution to prevent recurrence.

Safari will also run significantly faster.

No Factory reson