Are they actually discounted? Where I am in Europe they don't do that anymore, it's usually cheaper to buy the phone from Amazon - if you can afford the up front cost.
At least in the US, in July, for a Google pixel 8, through Verizon or AT&T, no. Buying a pixel 8 retail from best-buy or Amazon was $200 cheaper than either carrier, and both wanted to push financing instead of outright purchase. My experience (mostly with Verizon) has been that buying directly from the carrier has been more expensive in the last decade than buying the phone retail.