"classified information is ONLY supposed to viewed in a SCIF"
No.
No, no, no.
Most classified information is NOT designated SCI. When classified info was mostly paper, it was placed in GSA approved safes in regular 'ole office buildings. You'd get to work, open your safe, and do your work. Most SIPRNet computers are not in SCIFs.
Heck, you can even mail classified documents via USPS. Confidential and secret documents can be sent registered mail.
SCIFs are for viewing TS materials, whether or not they are SCI. Even then, SCIFs are often employed for processing things that are only marked Secret or systems only handling Secret. But yes, if we want to be specific, Secret has a lower bar and can be worked on outside of SCIFs but still not in public or at home.
No.
No, no, no.
Most classified information is NOT designated SCI. When classified info was mostly paper, it was placed in GSA approved safes in regular 'ole office buildings. You'd get to work, open your safe, and do your work. Most SIPRNet computers are not in SCIFs.
Heck, you can even mail classified documents via USPS. Confidential and secret documents can be sent registered mail.