Too many people spend their whole careers somewhere (lost wages, lost skills and atrophy) because they still feel like the company actually cares for them.
They don’t.
My late realisation (and at a cost) may be related to yours - your coworker is not your friend, better keep it that way.
Another related one: having friends become colleagues can be challenging.
In a recent interview I had, president of the company said "we're a team, not a family"