Yes I've noticed that too. For one example, compare Tom Petty doing Full Moon Fever with Jeff Lynne, and then a few years later doing Wildflowers with Rick Rubi

Yes I've noticed that too. For one example, compare Tom Petty doing Full Moon Fever with Jeff Lynne, and then a few years later doing Wildflowers with Rick Rubin. Lynne has a sound, and it's all over FMF. Rubin doesn't have anything distinctive in the final product of WF, but you read or watch things about the recording and he's talking with Petty about it the entire time.