The electric drive motor is about the size of a watermelon and weighs ~70lbs. Its easier to pull it and swap in a new one than to tear it down on-site.
If I think about it, no example comes to mind where I would be okay with paying much much more for something because the relevant technician says "I'll be easier for me if you buy a new one instead of me fixing this."
As another example, amputating a limb is relatively easy as surgery goes, but it will cost you your limb and you would probably prefer that doctors not do it for their own convenience.
The sum total of amputation is much harder than fixing the limb, assuming it's possible. Yes, it's easy for the doctors, but it's hard for you.
If fixing mold in a house is cheaper than building a new house, that's telling you that it's easier overall. It might look harder, but that's because much of the difficulty of building a new house happens off-site, in the felling of trees, mining of gypsum, fabrication of pipes and wires, etc.
If Tesla is doing warranty replacements instead of repairs it's not because it's "easier" in the sense that the technicians do less work at the expense of the company, it's because it's "easier" in the sense that it's less effort and money in total.