Getting a good .com is extremely hard. I find most of these .coms are available but are bought to be resold at high prices (in tens of thousands of dollars). Most people just go with .co or .ai or something like that, until they are big enough to buy a .com of the same name.

If users actually like what you built, they won't care if your URL ends in .cc, .io, or whatever. The obsession with a clean .com usually just masks procrastination.