Using a hard money lender is not the same as cash. You are still obtaining financing, just not from traditional sources. If you were using a home equity line or some other credit line that would be the same as cash.
A hard money loan is still a mortgage. The lender is going to appraise the house to be sure that there is sufficient collateral. It is just like a traditional mortgage except that it comes from a different source than a traditional lender. Now if you could establish a credit line or business line of credit that isn’t secured by the property then you can use that like cash. That is very difficult to do if you do not have an established business or a personal residence that you can borrow against.