You're conflating two ideas.

To be qualified for the role you need actual physical qualifications obtained through education and to "be qualified" through experience.

It is absolutely possible to hold too many qualifications (and be overqualified) whilst lacking experience.

You're conflating qualifications with "being qualified" through experience

Most of the people here talking about being over qualified purely mean in terms of qualifications - actual certified documents they obtained from educational institutes.

It is unusual to hear someone use the term "qualified" to mean "has relevant experience" and that's why you're getting so much push back here, because they're not generally considered to be the same thing.

Overqualified and under experienced is real feedback that many graduates with higher degrees get - I received that myself many times shortly after completing my first masters degree. I agree that it makes no sense, but that's where we are.

Also - 2-3 years relevant experience is not entry level any more, it's still early career but it literally is not targeted at the entry point of that field. The only meaningful entry level jobs are 0 years experience, they are for people entering the field.

If you are advertising entry level jobs with 2-3 years of relevant experience required in that field, and you're in charge of recruitment, how on earth does anyone enter your field???

If you hold a PhD, you may be seen as overqualified for many entry level positions, despite lacking the "real world" experience necessary for higher up positions.

The reason for this is possibly because employers assume that you'll demand a higher salary than typical entry level staff and that you will be at a different position in your life, because of your higher qualifications, yet you obviously haven't proven yourself in the corporate world yet, so they can't gamble on you performing well at an appropriate level.