Sometimes it is better to go on location.  And sometimes it is better to bring the location to you.  This depends on a number of factors.

Sound

One of the important issues with a production is the quality of the sound.  If you are trying to do an interview in a noisy environment, you may not be able to get satisfactory sound.  This could result from an open area where others are working, answering phones, running machines.  It could be from a room with uncontrolled reverberation.  Ironically, this is frequently the case in a conference rooms where media presentations are given.  And it could result from heating/air conditioning found in many commercial buildings.

Outdoor location can be even nosier.  You might expect noise from the street or a parking lot.  It isn't unusual to pick up highway and freeway noise from half a mile away.  And then there are jets occasionally flying overhead which completely destroy the sound.

Shooting in a sound stage in front of a green screen can give pristine sound.  An image or video of the location can be added in post-production that gives the appearance the video was shot on location.

Office Hours

Not everyone is available during office hours.  This is a particular problem when the office may be closed at night.  Or, perhaps you are doing a testimonial video where the person being interviewed isn't available during the day.  The studio makes those off-hours interviews a snap.  And using green screen, they can appear to be shot anywhere.

Graphics

Another use of green screen is applying background graphics and videos.  Perhaps it would be helpful to show video or graphics behind the person talking.  Green screen allows you to put the person in the graphic or on top of the graphic.  Then when no longer needed, the background can switch back to the original setting.

Time Shift

At times, it may not be possible to get participants in an interview or discussion together at the same time.  A substitute interviewer may ask the questions of the person being interviewed.  At a later time, another person, shot on green screen, can ask those same questions.  In post-productions, the two individuals can be combined giving the illusion that the interview was made with both people present.