Also, objectively, not the case but also rather irrelevant. Lots of session musicians will, by necessity, have technical ability but that is very different to having personality, style or the ability compose highly successful or original music.
Roger Taylor is a very fine rock drummer, one of the the best of the many 100's I've seen live in concert.
Brian May is a great rock guitarist (Total Guitar named him as the greatest in 2020). And whether you like his guitar sound or not, it is unique. Steve Vai, who is probably as technically gifted as a rock guitarist gets and can parrot most other guitarists, has made these comments about May:
“He has real quality, integrity, rock sensibilities – he has a phenomenal ear for the actual music, you know? His inner ear constructed that amazing tone that he has, and it always sounded great. And just the fact that he was able to build that guitar when he was young… that Red Special was hand-built by him, so it has a myriad of tones to it. “But all these tones and everything in his guitar, in his amp, are just one dimension. It all comes from his fingers and his mind.”
“And I’ll never forget that day, perhaps a few days after I moved out to Los Angeles when I was 20 years old, when I walked into the Rainbow Bar and Grill on Sunset Blvd and there was Brian standing at the bar. It was surreal.
I went up and just started talking to him and he was so so kind. He was interested and interesting, and I could not even believe I was talking to my guitar hero. He even invited me to a Queen rehearsal the next day. Of course I went and got to meet and see the whole band. It was kind of unbelievable to me. And there it was, The Red Special plugged into his Vox Rig. It was so odd to see this guitar in real time. And then Brian said, 'You’re welcome to try it.' It was just a few years prior that I was still ogling this guitar from my Long Island teenage bedroom, and now it was in my hands. Of course I played it, but to my chagrin it didn’t sound anything like Brian. All that magnificent tone is in his fingers.”
“… When I heard Queen, and all that great music of the ’70s… it held a special place that never goes away. “And lucky for me, they were all absolutely brilliant musicians. There’s nothing like that, nothing even remotely like it. It was like a paradigm shift, and what Brian was doing, and the way the stars came together with him and the band. And Brian’s whole overview of sound and guitar parts, there was just nothing like it."