If Sony continue with this price increase everywhere, and on the main regions such as US and Europe, I expect the sales to drop to PS3 levels weekly and monthly. Which will itself put a limit to probably 100M lifetime even with the gen going as far as 2028.
My sales comparison threads:
Ultimate Showdowns: JP 2023 / JP 2024 / 2024 / 2023 / 2022 / 2021
Global LT Showdown / Regional LT Showdown / Historical Showdown / YOY Charts / 140M+ Club Chart / Quantity of Games