All but inevitable is a bit strong, there were definitely rumbles of fallibility. Mas and carapaz looked strong and gave it a crack. Primoz's bad days just never seem to be all that bad. Incredibly consistent rider, maybe second only to vingegaard in that dimension.
You'd probably have to say he's the best ever GC rider to not win the TDF at this point. And doesn't look likely to with two untouchable guys ahead of him as he heads towards retirement.