Once again, one more “newbie” question, until you realize an account does not define the person behind it.

So, is
BTC really the ideal tool to replace banks in typical loans and mortgages, or is it only designed for big players and small-scale charity "loans" like we usually see in this forum?
Does this not look like a newbie question? that the forum does allow for loan does not mean that the whole usefulness of bitcoin for for such purpose and just for whales to make use of. on the forum, before you are eligible to get any loan, the collateral that you must have is being part of an active signature campaign which means that for those that are not in a signature campaign, they can not take up any loan and will have to opt for banks as the option to get the loan from.
bitcoin was never created as a substitute to the the banking system. the population of users that do not have access to the forum and bitcoin in general far outnumbers those that have access to it and so, it is not even reasonable to assume that bitcoin is a replacement to the fiat in terms of using it to take up loans.