Antonio Giovinazzi has claimed F1 can be "ruthless" when "money rules" after being dropped by Alfa Romeo for 2022.
The Italian will be replaced by F2 contender Guanyu Zhou, who will become the first Chinese driver in the sport's history and is believed to be heavily backed financially.
The move brings an end to Giovinazzi's association with Alfa Romeo and Sauber which began in 2017 when he stood in for Pascal Wehrlein at the start of the season before becoming a full-time driver in 2019.
In a social media post after his departure was announced, Giovinazzi said: "F1 is emotion, talent, cars, risk, speed. But when money rules it can be ruthless.
"I believe in the surprise of an unexpected result, of big or small victories achieved thanks to one’s commitment."
In a separate post, Giovinazzi added: "Unfortunately, we often struggle to find the right words to show our gratitude towards someone.
"But I think there's nothing more beautiful than being able to say thank you.
"Thank you for everything and those team members who have supported me through all these wonderful years.
"The biggest thank you is to my fans, who have always been close to me and made me feel their affection in every occasion."
Zhou's announcement completes the grid for F1 2022, with Giovinazzi moving to Dragon Racing in Formula E.
The Chinese driver will partner Valtteri Bottas next season, who makes the move from Mercedes.