i wouldnt be surprized if hes been gently pushed out. unfortunately the clarity of his voice has noticeably worsened.
listen to a 10+ year old episode and he sounds much clearer
as a native speaker its all fine and intelligeable, but for anyone ESL it'd be challenging bc its so much mumbling now
His voice is noticeably frail and less full of life in the last 4-5 years of episodes
I'm ESL, I'm Polish native speaker.
I had, and I still have a lot of issues with understanding his accent. It's very hard for me to get what he's saying.
Try the older episodes (go back at least a decade).
His voice had started to become a problem about 10 years ago, in my view. He also started finding it harder and harder to keep all the threads of the discussion in his mind and to herd all the experts and steer them towards productive talk. The earlier episodes were almost all great.