People can amass power in a system with sortition, but those people don't amass it in the role of office holders (in those offices subject to sortition.) Of course, the office holders aren't the people amassing the most durable political power in the current system, either.
If you don't think officeholders that are randomly chosen amateurs in the field that are guaranteed to be out of it in short time aren't very often going to be extremely vulnerable to manipulation by people whose interests are stronger, more permanent, and durable, then you haven't thought things through very well, IMO.
If you don't think officeholders that are randomly chosen amateurs in the field that are guaranteed to be out of it in short time aren't very often going to be extremely vulnerable to manipulation by people whose interests are stronger, more permanent, and durable, then you haven't thought things through very well, IMO.