Fearing Loss of Relationship is a Misconception
A relationship is not a thing. It's a shorthand for 'the set of interactions you have with a person'. But people often treat it like a thing. They do things 'for the relationship'. One could interpret this as doing some stuff in order to make other stuff better/longer/whatever, but I don't think that's how people think about it. They don't think about how or even whether the other interactions are affected.
If one is rational and has relationships to the extent one has shared interests with someone, that means the more you change your interests, the less you will have reason to interact.
This applies to romantic relationships, too. If you think of relationships as things, growth in different directions is a threat to the relationship. What this actually means is that if you grow in different directions (if you lose interest in stuff you used to do together), you will have less in common, so less stuff to base your interactions on, so you will interact less.
Because of this misconception about relationships being things, some people fear the loss of the relationship. But this is nothing to fear. Either the interactions will be good and they will continue, or they won't be and then it will be good to stop, and spend your time doing something better instead.
If one is rational and has relationships to the extent one has shared interests with someone, that means the more you change your interests, the less you will have reason to interact.
This applies to romantic relationships, too. If you think of relationships as things, growth in different directions is a threat to the relationship. What this actually means is that if you grow in different directions (if you lose interest in stuff you used to do together), you will have less in common, so less stuff to base your interactions on, so you will interact less.
Because of this misconception about relationships being things, some people fear the loss of the relationship. But this is nothing to fear. Either the interactions will be good and they will continue, or they won't be and then it will be good to stop, and spend your time doing something better instead.