I feel this is very short sighted. The main reason I pay for the highest tier Netflix account is, to have up to 4 people use it at the same time. These are all family members btw, but they’re often traveling, or using it at a friends house.
So if I am now the only one allowed to use the account, first thing I would do is downgrade to a cheaper tier, since me alone would never reach the 4 devices limit and I couldn’t care less about 4K.
Secondly, sharing my account with other is the main reason I don’t even think about the subscription going on now for many years. Because at least someone from the family uses and benefits from it. Once I am the only user, I could just cancel and re subscribe for a month whenever I am in the mood, eg when there is a new show I’m interested in. Then cancel again. In the end Netflix would get possibly 20% the money from me that they get now. Am I really the only one thinking like that?