Isn't that what independent reviews are generally useful for? To try all the options and share feedback for someone to make their own choice.
Yes, if you can even get your product high enough on the rankings to make a sale.
The incumbent has a massive advantage, making it harder for a new (but better) product to get on the first page.
For every kind of product one might need to buy?
How do you get someone to review your product if you're one of N? Paid reviews? Not independent anymore. Paying money to get some exposure and sales is the best of all bad options.