I'd rather have 20% APR, than give away 20% equity. Why? Because when the debt is paid to the credit card company they go away. The VCs will always want more and more, pushing your company faster than it should go.
30 with 3 kids and no savings? Yes please, give away some of my profits so VCs can derisk the startup.
20 and living with parents? Bootstrap away, if I fail I will be fine.
Fund-raising takes a lot of mental space on its own which comes at a high premium when you're focused on finishing a product.
Even with $50k at 20%, we're talking about $833 a month in interest, that's not that much to someone who would usually make $100k+ at a job if they fail.
Opportunity cost is the real liability.
I wonder how common that funding level was in the late 19th Century.
Rockefeller did that for example before creating Standard Oil. He built up a sterling reputation first working as a bookkeeper, then as a partner at a trading firm. He got to know the owners of capital in doing so. At times during the early years he required extraordinary sums of capital, his reputation enabled him to raise it in an evening by riding around town and meeting personally with bankers. He did that once to buy out a large shareholder who had become conflictory; and other times to acquire businesses quickly.
Henry Ford went through multiple iterations of messing around with commercializing his creations (including the Henry Ford Company), before finally founding The Ford Motor Company. After his very early experiments with vehicles, his later efforts all required the support of financiers and lots of capital. Over time he had demonstrated a knack for pulling complex engineering efforts together and attracting talented people.
Edison always had capital backers for each of his major commercialization efforts. He operated his own lab (at times funded by outside capital) and then typically made arrangements for each set of inventions with financiers to take them from prototype to commercialization and distribution. Nikola Tesla had some similar backing arrangements at times, although his history in business was even more haphazard.
Before George Westinghouse founded Westinghouse Electric (which is what made him particularly famous in the era), he started with The Westinghouse Air Brake Company, which he founded at 23 years old. And even before that, he started by creating useful industrial inventions, receiving the first patent for a rotary steam engine at 19 and a bunch of smaller railroad-related inventions, before striking commercial gold with the air brake.
The Wright Brothers blew a lot of energy defending their patents and not competing in the market.
The balance between hard skills, showmanship and ruthlessness would be an interesting study.