It does wear down Ukraines resources and military - such as they have there. It’s been and will continue to be a blood bath for both sides....
Such a statement can be applied to any scenario of combat. But the specific claim was that the purpose of Bakhmut was just to serve as a meat grinder for Ukrainians. But here, Wagner is explaining that each house is a fortress and it takes them days or weeks or months just to take a single house. Such situations indicate high attrition on the attacking side, which also explains why they complain of being low on ammo and everything else.
So, who to believe? The Putinist arm chair generals, such as yourself, fantasizing about Russians killing thousands of Ukrainians at their leisure, or the actual Russians who are giving excuses for their dismal failure to take Bakhmut after more than 3 or 4 months of combat?