How astonishing - even laughable - that you, a relatively inexperienced punter, dealing I gather with down-market Romanians, think you know more than Strawberry, a knowledgeable professional who has been posting on here for 11 years.
You can't really say how busy everyone is. Some may limit themselves to 1 or 2 clients a day, others may run a production line from touring in a M62 Travelodge.
Some respond quickly saying they're free, others tell you tomorrow, and some just will not respond at all - are they so busy they just can't work through the list of potentials, can they not be bothered, or just be in a position where they can turn away paying customers as they don't need the cash?
There are some on here that get positive after positive reviews and therefore are harder to book. Unless they specifically tell you how many clients they see a day, week, month, year, it's just speculation.