I have not tried a Pixel 4 but I just got done using a OP 7T for a couple weeks alongside my iPhone 11 Pro and I was VERY close to ditching Apple. The 7T is really better in every way except for slightly worse photos, slightly worse video recording, and no iMessage. If I wasn't so tied to imessage with my contacts I would've stayed with the 7T in a heartbeat. The display is great, 90hz on the screen is amazing, the gestures oneplus does is very close to iOS gestures, the phone flys in terms of speed and graphics, warp charging is insanely fast. Still having a wide angle lens is great and I found it right on par with the iPhone. The ability to take macro shots is really cool and not even possible on an iPhone. The in screen fingerprint ready worked really well, and the face unlock is lightning fast. OnePlus has a bunch of very nice features built into their launcher for customizing stuff. Like I said, I haven't actually used a Pixel 4 but if I had to guess the only upside to it is a slighltly better stills camera. From everything I have read their video recording is still garbage, there is no wide angle lens, theres no macro shot, less ram than the 7T, and it is more money. I think between these two devices, unless you absolutely need the greatest still shots, the 7T is far and away the better phone.
Honestly, I kind of regret sending mine back. Damn imessage lock in.
Edit: oh yea battery life...I was getting very good SOT on the 7T.