>AFAIK at this point most of the "ripping" of decryption keys/etc for streaming content happens not by attacking the TPM, but by using android devices that are allowed to skate with reduced security modes, and just having a giant stack of them so when one device gets banned they throw it away and move onto the next.

Without a TEE (eg. trustzone), you're not going to get anything above 540p, at least with widevine. Note TEE is baked into the SoC itself, so while it's not impossible to find a bug, it's much harder than finding a exploit in android or system apps.