Depending on your indebtedness (outstanding student loans, mortgages) savings and current earnings a bank could still refuse to lend you enough money, if at all
I had no trouble getting an uncollateralized loan at a reasonable rate for $75k; and I had $100k in student debt, a $500k mortgage and little else in the way of assets. And when I say “no trouble” I mean I applied for the loan, was approved 30 minutes later and had the money in my bank account within 2 hours. That loan is paid off now, but if your income is high enough banks will lend you money on that alone (I was making an equivalent salary to a principal developer at the time).
Its nice everything worked out for you, that has nothing to do with your ability to perceive a simple solution available to you.
Bigger risk comes in if someone wants to do an exercise and hold to sell much later, which can bring tax advantages. But this is a different game entirely. In the case of employee with little spare cash (to the tune of borrowing money for the exercise), not doing exercise and sell is really leaving money on the table. My 2c.
What goes on between the founders, board, current investors and likely future investors is likely known to very few amongst them, if at all.
Even if you believe strongly in the product and know the market-fit is bang on, you don't know if the option is currently priced correctly.