Why we need to insert SIM card for startup

[phani]

Why we need to insert SIM card booting a new phone which was bought from Samsung..

Model : s21 ultra 

If I insert SIM it's adding blotware of Operator.

Why Samsung you throw this shit on a 1600$ phone

[BCSC]

before carriers were forced to sell unlocked phones this was a manner in which it would lock it to the correct carrier after purchase. my understanding is they all shipped unlocked until the SIM card was installed.

[phani]

worst thing is you can't setup phone without SIM