There are 7.7 billion people in this world (https://www.worldometers.info/world-population/). On an average, you can ‘have stable relationships’ with a maximum of 150 people only (https://en.wikipedia.org/wiki/Dunbar%27s_number). That’s a huge number for anyone to include toxic people in their prime list of relations, isn’t it? Why ruin your hot 150 by including 1 or more toxic persons when you can safely discard said person(s) in 7 billion minus 150? (they’ll be lost in subtraction, which is a definite win-win).
Just like basically everything else in this world, friendship is an ever-changing phenomenon. Why? Because people change. Situations change. Ideologies, habits, practices and ambitions change. The relationships we’ve built with people follow, and we need to make dynamic decisions – do we still want to continue, adapt or overcome?
As a rule, I’d say we count on nothing to stay forever. Not in a pessimistic, negative way though. I find this thought actually makes me a happier, more positive person, because I end up working to cherish what I already have, and I tend to work towards it now. Why spend time thinking what might happen, what if it doesn’t work out, when you can make it work right there, right then? We shouldn’t count on anything to stick forever, just as we shouldn’t count on problems to take care of themselves either. Fight them as they come.
That said, there’s always a lingering doubt about certain relationships we have. Are they worth it? Are they draining your energy rather than charging it? I believe there’s always a need to step back, take your time, and assess the situation. Especially is the said relation isn’t bringing you joy.