This is a personal decision for everyone, but there are some key advantages to a loan (as a Deposit Booster) over gifting.
Here are a few:
You may not like the idea of giving a handout but are willing to provide a necessary leg-up to get them started.
You may need or want the money back in the future.
You have options! You can always gift part or all of your stake later.
You may be wary of a beneficiary breaking-up with a partner and seeing the money go out the door with them.
You may be able to help multiple children onto the property ladder with the same pot of money.