Most of the businesses in the list are very easy to copy. There are neither rocket science, neither patents to protect them, neither big money to pay lawyers to protect their work.
Knowing how well the product sells, you can copy it piece-by-piece by saving a lot of time trying different approaches. Author of original product already did all the hard work guessing what will work the best. You just come, copy and profit from his work.
This is not true. People who copy will mostly do it for money. Finally the passion for the idea trumps the desire to chase money and your product will eventually suck. On the other hand if you think you can make a better product from existing solution, then there is a good chance of you succeeding.
You can try copying any one of those of ideas for money and see for yourself.
>Finally the passion for the idea trumps the desire to chase money and your product will eventually suck.
I think his point is that the ideas being shared are simple enough not to require that much passion to implement, and the goal being not doing something better, but something economically viable (good enough to generate income).
The obvious counter-question would be: why would people use the worse copy instead of just using the superior original? The answer is that it could be the case for a variety of reasons, one of which is cultural relevance, the original filters geographically, is not internationalized well, people do it differently in different regions, etc. After all, you find companies doing similar things in the same market, it only makes sense there's chance of finding other companies doing the same in different markets (given the conditions to implement the idea are already in place: not that easy pulling an Uber/Lyft in a country where mobile broadband and payment haven't matured).
You're not entirely wrong, but building most products is easier than finding the right audience and being able to sell it to them. That's the business.
From my experience copying a feature is about twice cheaper than trying different approaches. You may not figure out a good way to implement it until you build first version and let people try it. You may need re-iterate to find perfect implementation. The copy-cat will come later to see what you've done and will implement the good solution without iterations.
Knowing how well the product sells, you can copy it piece-by-piece by saving a lot of time trying different approaches. Author of original product already did all the hard work guessing what will work the best. You just come, copy and profit from his work.