why u should not lock bootloader

The main reason for locking bootloader is sell mobile or give to the next generation (family)
But locked bootloader didn't ask for food let it be,
If something went wrong realme doesn't provided flashing tool so u have to go to service center ,
As well if possible don't downgrade device it's also not recommended becouse some device get in big trouble eg my old moto g5s plus loss IMEI
Tso follow as per wish