We have the internet now. You can look up how to do these things.
And regarding renting from the hardware store: it seems to work out fine for most people, but I got a blower that didn't work right (since hardware stores don't maintain rarely used tools well) and that made it take a lot longer than it should have (mostly driving because I don't live anywhere near a hardware store or tool rental store). The worst case scenario if you make this mistake is that you return your (free) hardware store rental and go to a tool rental store anyway. I'm just trying to save other people time if they try this.
We have the internet now. You can look up how to do these things.
But where do you get the knowledge to know that you picked the right guide off the Internet and that it isn't going to violate housing codes that don't exist in the area of the person who made the guide? Or how do you know that it isn't going to have a long term chemical reaction with the floorboards because the guy writing the guide didn't have such floorboards and didn't bother to mention the possibility? Or any of many things that could go wrong? You need knowledge in the first place ...
Two of the main resources people have are time and money. The world offers many opportunities to trade one for the other, at widely varying rates.
Where do you see people trading money for time at unfavorable rates - spending too much money to save too little time? What things should people just DIY?
See also the flip-side of this post, "what are you surprised people don't just buy?"