When I was applying for PhD I was considering Germany, UK, Austria and Switzerland in my search for a position. So far, I found that each university/region has their own policies in application submission process.
For instance, I found that most of the Swiss universities ask for a direct recommendation letter from the recommender and it is not acceptable to submit it as a general one and it is only acceptable if it's sent directly from the recommender's institute email to the target university. In contrast, in Germany where applying now at a higher ranking university than the Swiss one, professors, and universities are more flexible and accepts them as a general one, so no need to be specifically produced for the particular university.
I tried hard to find a place in Swiss universities, but I ended up rejected with no response from my previous professor as it considered time consuming for him, and I don't blame him since general recommendation letter is enough in other universities.
Do universities that ask for such a thing consider them self better than the others and will lead them to better candidates?
The question is, why such universities make it hard for the student who apply for PhD? Is a general recommendation letter (I have 4 letters from different professors) from your previous professors where they indicate positivity about the candidate enough for such a PhD application?