Firstly, using a VPN ultimately consists in trusting the company providing the VPN service that it won't be fucking around with your privacy. Considering that all your traffic goes through it, that's a lot of trust to place in one company. And I generally don't trust any tech company to resist the lure of selling your data for profit for very long in 2024 - even those that profess to be privacy-friendly.
Secondly, modern corporate surveillance doesn't rely on IP addresses anymore. So if you think a VPN protects your privacy, it really doesn't. All it does is tell Google et al. which VPN provider you're a customer of - i.e. you're giving them even more data that they don't need to have.
That's why I don't even bother with a VPN. I only use one to evade geo-blocking every once in a while.