That's a strawman , having wannabe competitors does not absolve them from their anticompetitive practices. "Facebook" is a web-based social network. They weren't competitors to snap-tiktok-telegram-discord . But then they bought instagram, they bought whatsapp, they built a copycat messenger and used facebook+ig to push it to everyone, they copied snap and pushed it to everyone, they copy slack and push it to everyone, they copy tiktok to push it to everyone ... you see the pattern here, using their earlier dominant position to destroy any chance of competition.

Because - all the companies I listed above are now bankrupt and gone?

they dont need to be bankrupt to be wannabees. Wordperfect and myspace still exist

(plus yes, a lot of those companies would go bankrupt without their VC funding)

Amazon has competition from online stores like ebay, AliExpress, Wayfair, and Overstock. Traditional retailers like Walmart, Target, and Best buy also have online presence challenging Amazon. It's pretty trivial to cut them out of your life. They don't have much that you can't get elsewhere