any idea why is google so biased?

Biased how? If you mean it favours big brands, partly yes, sites with lots of links, mentions and history are easier to trust, so a new small site has a harder time even with a good page. If you mean favouring its own stuff, that's a real thing too: YouTube results, Shopping boxes, maps, AI overviews all push organic links down. The EU fined them over exactly that with shopping results. Neither is something you can fix, you just plan around it.