The people who need a loan, will not be the people affected by AmazonBasics. AmazonBasics will only copy extremely well selling products. If you need a loan you do not have an extremely well selling product.
I was with you until your last sentence. There are plenty of extremely highly successful companies selling products at a very high clip that require credit facilities (aka loans) to finance the selling of their products. The reality is this- to get scale you put out a ton of cash before you sell the product- a loan helps you offset that timing and spreads your risk to another party.