Seems my topic title was too vague, sorry for that!
For others, who will also look for this question: after having searched the forum more thoroughly, it seems there is not a real agreement on this. PG’s overview How Do VPNs Protect Your Privacy? Our VPN Overview - Privacy Guides says
When isn’t a VPN suitable?
Using a VPN in cases where you’re using your real-life or well-known identity online is unlikely to be useful. Doing so may trigger spam and fraud detection systems, such as if you were to log into your bank’s website.
Which is not really against it but doubts the usefulness.
Also, other related topics (again with no clear conclusions) are:
Other topics in this forum and their titles:
Using vpn on accounts made with real IP adress [can’t insert another link]
Privacy Questions and Answers [can’t insert another link, search for the term “identity” here]
This topic can be closed then 
Cheers!