I think the success of this will depend on the number of tenants who are willing to use this platform, as landlord will go where the tenants are. So from tenant's perspective, what are the benefits for using this platform?
Tenants are actually paying 10% extra just so they can avoid the deposit upfront (correct me if I'm wrong), so for those who can afford the deposit, I don't see any benefits for using this platform. Even if I were to put the deposit saved in a fixed deposit, the interest generated will be far lower than the extra 10% I have to pay every month.

Even if this is true, there are other medium out there for you to borrow small sum of cash (Ex: Bank Personal Loan...) to pay rent deposit, which I think has much lower interest than the 10% extra you have to pay every month. And if you can own a credit card, I don't think there's any problem for you to get Bank Personal Loan approved.

Interesting Thankfully my tenant is still paying rent on time, this might be handy for those who have trouble getting tenants to pay up