But the Ospreys man is in no doubt that Wales are in good hands with the likes of Sam Warburton and George North earning plaudits as Warren Gatland led his side to a fourth-place finish at the World Cup.
And it is the leadership of Warburton in particular that gives Williams hope that his compatriots can continue his legacy, starting with next year's Six Nations crown.
"This is the most talented group I've ever worked with in a Welsh squad," he said.
"I'm sure there is a future there and this team is capable of big things and we will be seeing a few more Grand Slams in the not so distant future.
"I'm very confident about this group of boys and the confidence they have got between them is mind-blowing. They believe they can win things and that is great to see.
"It just proves really the confidence these young guys have got. Sam has been around a long time already but still very young and is a player who is one of the best in the world in his position.
"He can only get better, which is frightening really. He's an inspirational leader and everyone looks up to him and admires him so it's going to be very interesting watching Sam develop as a player and captain over the next few years."