Well, why use a VPN:
- Prevent ISP's from intruding on your privacy.
- Get a public-facing IP in another location, to overcome regional restrictions.
- Be able to get some better routing to the world, when located in a country with bad internet connections to the outside world.

Nr 2 is clear. Nr 3 will be too difficult for most to understand, so I leave it as is.

And number 1: Yeah, have a Google VPN, so they really can track what you do, now not only on 1 device, but also over multiple devices, so IF privacy is your concern, don't use the Google One VPN. Its main target is to intrude on your privacy (serve you better with stuff they earn money on, not what you need) and at the same time, lock out the competition to collect privacy-relevant details, to which now only Google has access. Let's not forget, the original Google mission statement of "don't be evil", has been dropped a long time ago.

ExpressVPN: I don't have experience with that brand, though went for ProtonVPN because of the principle privacy approach they have, and being originating from Switzerland. Privacy is not something many if not most commercial VPN providers have as a target, their primary goal is making money, sacrificing one's privacy when whatever government asked for account owner details. Not to say, probably selling the collected privacy-sensitive info to the highest bidder, just like several (professional) virus scanners do.

So, if one wants privacy, scratch the head, about one's VPN brand selection.