I'm glad you've never had a problem with it. But sometimes people do leave jobs rather than simply move to a new job on good terms. I couldn't imagine being forced to work in a job that I no longer wanted to work.
If something changes at work or in my personal life and I no longer want to work at my job, I have the right to say "goodbye", and leave immediately, and I wouldn't want it any other way.
If you've seen an American TV show where someone says "I quit!" and walks out the door, that isn't just a trope. I know people who have done that. As should be their right.
If an employer ceases to be professional, reasonable, or safe, there is not a damn thing wrong with immediate termination of employment from the employee’s end.
If an employer can terminate the agreement for just cause immediately, why can’t the employee?
It offers me no disadvantage. Only upsides.