Why and how were the PS5 and RTX 3080 bought by Scalpers / Bots?

I've read that the PS5 and the NVIDIA RTX 3080 were bought by bots so that nothing is left in the end. Can someone explain why? How works

So that they can sell it on Ebay for more money.

Thank goodness there are people who run bots to bid in auctions e.g. In the 5-digit range ^^

First of all, the structure of the web shop front end - i.e. The part of the web shop with which a user typically interacts during the purchase process, such as input fields and buttons - is analyzed by the bot developer. Building on this, the bot is programmed in such a way that it is able to replicate the clicking and typing of a human user. The routine of such a bot then starts with repeated calls to the web shop at the publication time communicated by the retailer, until the product sought is actually available in the web shop. Then click on the "Add to cart" button, enter the user name and password or the address and payment information of the buyer, and finally click on the "Complete purchase" button - in a fraction of a second and without any human intervention.