Above average in which group though? If it's a competitive field where only the people with relevant PhDs get called back in for an interview, then you need to be at the top end of that group to get a job. Being above average in some broader population doesn't really mean much.
(I don't know OP personally and I'm not commenting on them specifically, they could be amazing)
In my (limited) experience there is definitely a bonus for being the very best but I also believe the London Quant job market is big enough to get a decent quant job without being IMO material.
(I don't know OP personally and I'm not commenting on them specifically, they could be amazing)