I read the words often. You do too. "In the preceding paragraph," is one example. "As mentioned previously" is another way lazy writers attempt to connect the dots of a persuasive argument for a reader.
It's a lazy way to write, and it's a dumb way to write.
It's your job as a writer to present your case to a reader, and your writing should make the logical connections for the reader. When you do not do that and instead point out the geographical location of ideas in your work for the reader to see, remember or reread, you are making a great leap of faith and being lazy at the same time: in forfeiting the responsibility to writing the transitional phrases and sentences that logically link your ideas for the reader you are trusting that the reader can make those leaps for him or herself. Now, ask yourself: how many people can successfully read your mind? Let's assume everyone can. Now, ask yourself: how many people, after reading your mind, will axiomatically agree with you because they think you're right about everything? If your answer is "everybody" then go ahead and point out the geographical location of ideas in your work because all of your endings will be happy ones. That's what life is like in a fairy tale.
However, if you live in the real world with the rest of us, then reconsider pointing out the geographical location of ideas inside your work. Don't let the example of others convince you that it's fine because a lot of people do it. That bandwagon is as deceptive as bandwagons everywhere; just because it goes by doesn't mean you have to jump on it
Think for yourself instead, and write for your reader. Write the transitional phrases and sentences that your reader needs to follow your point of view and agree with you because your argument is logically sound and they can see the connections because you have provided them. If you don't, your reader may go looking for the place you have pointed out and not come back to finish reading, and ideally, agree with your conclusion.