I know that there's quite a bit of disparity between the numbers of both of these products.
At the end of the day, it really just boils down to just picking one.
Both products have their own strengths and weaknesses but both of them are the biggest names in paid SEO tools for a reason.
You don't become a big brand in this highly competitive industry until and unless your product can deliver results.
So at the end of the day, it's not really a question of which is better, Ahrefs or Semrush.
You just have to pick one and know your tool inside and out.
Learn to use it the right way and everything else will fall into place.
As for myself, I've selected Semrush but I've also used Ahrefs in the past.
As far as I'm concerned, BOTH are good options.