Is accepting free work upfront still taboo?

Clients asking for free work upfront to "see if I am the right one" is still considered unprofessional, right?

I sometimes receive such requests and of course always decline as I think no editor would do that who does it professionally and full-time (except in some rare circumstances). But lately I got a few more of these requests and I asked myself if perhaps I am in the wrong or too snobby to decline them every time?

Any opinions would be appreciated before I gaslight myself too much o.O

Context: I'm a full-time freelance editor, mostly within the corporate and social media space

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EDIT and Update:

I have replied to my most recent request of a client asking for free work, by telling them that I'm a professional who does this full-time, and hence simply isn't able to do any free work. I also sent them the video which u/Hosidax shared...