Technology

Commercial VPNs as a security measure are pretty much a scam, at least in the way they are marketed.

These days, basically any web traffic is encrypted through HTTPS. Even on an untrusted network, nobody will be able to see the actual content (passwords, personal data) of what you're doing. DNS spoofing isn't viable either as any fake site they would send you to would lack the right certificates to establish a convincing HTTPS connection. So all someone can see is what servers you're connecting to, either by logging your DNS requests (can be prevented by using some form of encrypted DNS like DNS over HTTPS) or the IP addresses you connect to. And honestly, how much value does one get out of knowing that there's someone on their network who browses beehaw.org, supergreatbank.com and bigtiddygothgfs.to with no information to connect that to an actual person?

Unless you routinely use shady open Wi-Fi networks - and I'm talking about something that may have been setup on purpose by a malicious actor, not your local supermarket - to do security-critical stuff, you don't need a VPN. Also, if you trust your mobile data provider less than a company that tricks people into thinking you absolutely need their product to secure your data, you should get a different mobile data provider.

Now, there are use cases for VPNs but those are more along the lines of accessing stuff that's not available in whatever region you're currently in.

See also Tom Scott's video on the topic. It's a few years old but still relevant.

Edit: there is of course also the use case of hiding illegal stuff. In that case, I will not give any advice. Put some onions on top of your router or something, that's probably cheaper and more reliable.

Edit 2: just to make this entirely clear, I'm talking about commercial VPNs like NordVPN, Surfshark and whoever else pays YouTubers to advertise for them. If you host your own VPN, some of the downsides may not be as relevant. Though I would assume that anyone who even considers hosting their own VPN has enough technical knowledge about how networking works to know about the pros and cons.