Counter example: Tor is free, but does it make your security and privacy worse? I'm fairly certain it doesn't.
Tor is completely different to a VPN. Tor uses layers of encryption, so even if one of the three nodes you bounce through is malicious, there is very little it can do with the information it has.
Your entry nodes knows your real IP and the IP of your middle node, but knows nothing about your final destination or your data.
Your middle node knows the IP of your entry node and your exit node, but knows nothing about your final destination or your data.
Your exit nodes knows the IP of your middle node and the final destination of your data, and can also see your data if it isn't otherwise encrypted (such as HTTPS).
A VPN server on other hand can see your real IP, your final destination, and all your data, making it a single point of failure/attack/maliciousness/etc.
Monitoring traffic and selling data are big accusations that needs to be proved or it didn't happen.
Have a read of their privacy policy:
https://www.opera.com/privacyOur applications and services include third-party technology or code, some of which may use your data in different ways. When such third-party technologies use previously collected data, they typically act as data processors for us. When they collect data on their own, they typically act as independent data controllers. For convenience, we have included links to their privacy policies below. Data controllers are marked with an asterisk.
It then goes on to list some of the worst privacy invading companies in existence, such as Google and Facebook.
Side note: You are encouraging "good" paid VPNs, it's not always the right choice. Even paid VPNs are allowed and able to give out user's informations Example?
I used the word "good" to refer to being allowed to change servers freely, which is indeed a fairly basic feature that most good VPNs should allow. I made no comment regarding VPNs storing logs. I also wouldn't call HMA "good" in any sense of the word - they are based in the UK (five eyes), and again have a privacy policy which permits them to collect far more data than they should.