Without proper anti-trust and monopoly enforcement, no, small businesses cannot compete with megacorps who have giant war chests to fund the literal destruction of whatever niche you call your market.

Megacorps are destructive to market forces in general.

Small businesses died because we fed all the IGAs to Walmart, through Reagan's absolutely braindead "what if we just don't prevent monopolies?" policy.

It turns out, destroying the economy of local communities so that Walmart shareholders can be even wealthier while average Americans only get a few cents cheaper on some products.... at least until the monopoly has consolidated control and can just keep raising prices for the rest of history while selectively dropping prices anywhere someone tries to compete only serves the goddamned shareholders, not Americans.

Most rural places had small grocers. Now people who live in those places have to drive an hour to Walmart, and the local economy no longer has anyone working at the local grocer. The building that used to house the local grocer now has a fourth generation of whatever sketch dollar store company bought it this year, which employs exactly one human being from the local community, and the products are terribly priced, meaning not only did we lose the money staying local with whatever kind of more expensive IGA we replaced, we didn't even get better prices for it!

Monopolies are a huge percentage of the problem. America's rural communities are dying partially because all the local businesses have been replaced by national behemoths so literally every single day to day purchase you make ships more money out of the local economy. Nobody can have a job in a rural community because every dollar that finds its way to that community gets shipped out to Walmart HQ instead of flowing around and paying tradespeople and buying local products and services.

Sorry, it would have been more correct to say that while smol businesses are viable, Republicans and other corrupt politicians siding with big business is just them siding with the winning side.