I don't think that's the charitable perspective at all tbh. A charitable perspective would be that acknowledging "true love" isn't a thing and all love can end is a healthy way to look at things. If it's an all prevailing thought that you never stop thinking about or letting go of, not so good, but if you're just keeping in mind that even the best relationships can fail, and nothing is fated, then you're far less likely to overlook fatal issues in your relationship that would lead you to staying in a toxic one. And wanting an easy way out if it does become toxic is never a bad thing, because like it or not, that can happen at any time, no matter how compatible you were before.
My ex and I had an amazing relationship for a long time. I thought she and I might be fated to be together. But one day, things just started going down hill. Life stresses started building up, expectations of what we wanted from each other started to diverge, and we started fighting, a lot. Still, we wanted to believe it was fate, and that it'd work out. We had so much in common, we'd done great so far, so we should be able to make it through. But things only got worse and worse.
The thing that finally broke it up was when my now girlfriend tried her best to attempt a polyamorous relationship with us, and ended up realizing it was toxic as fuck and stealing me away from it.
In my new relationship, I've found it a powerful tool to remember always that there is no fate, something could happen and we could break up. I'll enjoy it as long as it lasts, maybe forever if it does last that long, but letting myself believe that's definitely gonna happen just isn't healthy.