Why can't Free-RTOS run tasks in SVC mode

hi ,
I am new to free-rtos , so please excuse for such a basic question .

Any specific reason for running Free-RTOS task in system mode .
Why can’t we let the task run in SVC mode ,what advantage are we getting by switching to system mode ?
Will there be any issue ,if let task run in SVC mode?
Running free-rtos on cortex r5 .

The two modes use different stacks, which FreeRTOS uses to minimise the amount of stack space each task requires. If interrupts and exceptions didn’t have a single separate stack then every created task would not only need enough stack for its own usage, but also enough stack for potentially nested interrupt use too - so that space is allocated lots of times (once per task) rather than just once.

There are other benefits too:

  • It enables easier use of different execution privilege modes.
  • It enables easier interrupt nesting implementations.