Well his 10 year performance is 255%. Which does not include his bet in 2005-08. Buffett has only done 154% in that time. So rumours of his demise are greatly exaggerated.
Also, his returns aren’t really impressive compared to VTI, which has had an annualized return of 14.04% over the past 10 years according to Vanguard. That works out to 372% total returns in that period.
It’s easy to make money when even the broadest US index fund is up by that much.
A joke said of Trump, of whom it is much more fair, but still...