Could switching carriers explain all these phone problems?

Those symptoms can fit a phone that isn’t connecting cleanly to the new carrier, without pointing to anyone deliberately interfering with it. Check whether the exact phone model is compatible with that carrier, then ask support to confirm the line and SIM are provisioned correctly. Carrier settings and the data settings used for picture messages can also need updating.

Battery drain can happen when a phone has to work harder to maintain a weak connection. Try the phone in a few different places and compare it with another phone on the same plan in the same spot. That helps separate a coverage issue from something specific to your device or line.

I’d start with the basics before buying another phone: restart it, install any available system or carrier settings updates, and check that mobile data is enabled. If that changes nothing, ask the carrier to check the account setup and try a replacement SIM if they recommend it. Since calls and internet are affected together, it’s worth having them troubleshoot the line, not just the photo-message setting.

Bars are not a great apples-to-apples comparison between carriers, and coverage can vary a lot by location. But the combination of failed data, photo messages, and calls over mobile data is enough to justify a proper support check. A controlled test with your SIM in another compatible phone, or another SIM in your phone, can help identify whether the issue follows the line or the device.

The symptoms by themselves don’t show that a company sabotaged the phone. Get the carrier to document what they tested, and if the phone still behaves unusually, have the device maker or a repair shop check it before spending money on a replacement.