Less stress with personal one to one attention
No commotion going on with multiple dogs being done at same time, multiple groomers carrying on, dogs barking, etc..
Pet is done at their home where they feel comfortable
Climate controlled air and heat, fully self contained
More convenient for pet and people
No sitting in cold hard cages with other dogs barking all day waiting for their turn to get groomed, then put back in the cage waiting on owner to pickup