I will explain the context of my statement to avoid misinterpretation. I believe you are referring to a thread few months back which posed the question that why Donald is underrated compared to some of the other legendary bowlers.
There is no doubt that Donald is one of the greatest bowlers ever. I'd say he is better than Steyn, but it is natural for him to be underrated by many people because he holds the distinction of pulling off the biggest individual choke in cricketing history. Well at least in the era of video footage.
The fact that he was not able to win SA a World Cup and in fact, prevented them from making it to the final is a major reason why he is less popular and influential than bowlers like Wasim and McGrath. Wasim's stock as a cricketer would no doubt have been lower had he not produced a match-winning performance in the 1992 World Cup final. In fact, the consecutive deliveries to Lamb and Lewis are the two most famous deliveries he has ever bowled.
Similarly, Imran Khan is one of the greatest Test all-rounders of all time and he was already a legend before the 1992 World Cup, but today, the World Cup win is considered to be his biggest achievement, especially among the casual fans and they are the ones who make up the majority and determine if a certain player is underrated or overrated. Ask any random fan in Pakistan and he won't even know that Imran pushed the ATG WI team in Test cricket like no other captain, and that is because World Cups are much more iconic and are etched in our memories forever.
Stokes no doubt choked in the WT20 final last year and prevented England from becoming the first team to win two WT20s, and if he does not perform for England in World Cups in the future, it will be a big stain on his career and will dent his popularity. On the other hand, if he playing a starring role for England and wins them a World Cup, it can prove to be the difference between him ending up as a great player or a legend.
Same goes for the likes of Root, Buttler etc. who can etch their names in history by helping England win the World Cup in 2 years time on home soil.
As far as the comparison with Botham is concerned, I believe he has the potential. He is one of the most talented players I've seen in a long time. Yes he is mediocre with the ball at the moment, but he has considerable ability. He is faster than Botham ever was, and he looks dangerous when he reverses the ball. Botham however, swung the ball a lot in his peak but Stokes is more of a hit-the-deck type bowler. Obviously in terms of performance, he has long, long way to go, but yes I do think he has the ability to overtake Botham.