Back in the mid 90s I had a Cadex carbon tubed frame with bonded aluminium lugs. I rode it pretty hard for a decade and there were no problems with the bonded joints. I eventually sold it to a work colleague and it was still going strong.

In the early 2000s I also had a Cannondale mtb with carbon chain stays bonded to an aluminium frame. Again no issues with the joint.

It really comes down to the quality of manufacture rather than the mixed materials. Bonding carbon to metal is fine when done properly.