People with work experience may be able to describe their experiences at length, but for HR, they prefer to see only a simple and clean resume.
Moreover, the resume is made to get an interview opportunity. If it is too long, it will appear to be procrastinating.
Generally speaking, HR will only spend 20 seconds scanning your resume and then decide whether to interview you. So, your resume is not for reading, but for scanning. Too many pages are boring, so the more concise your resume is, the better the effect will be.
Moreover, hr knows what kind of resume he is looking for and what kind of person the company needs before reading the resume, so the nonsense on the resume will not give any extra points to job seekers, and those empty and lengthy resumes will only be thrown aside without hesitation.
Therefore, one page of A4 paper is generally enough to apply for a position. Most hr people like to read "sketched" resumes: not many sentences, but many sentences, and basically the job seekers' own experiences are expressed in their own languages. The content of one page can fully express a person.