I think lots of people have the wrong idea of what 'toxic masculinity' entails. They think it's masculinity which is bad because men are bad, and that's toxic. There are problems with the category 'the masculine' ofcourse, but that's seperate.
What I think it is, is masculine traits taken to their toxic extreme. In this way, self-reliance becomes self-isolation, assertiveness becomes inconsideracy, emotional resilience becomes emotional repression, and confidence becomes arrogance.
Men feel societal pressures to "be a man", and when they feel they don't live up to the expectations, they overcompensate. The problem is, ofcourse, not something intrinsic to men (this would be gender essentialist), but rather, the categories of 'the masculine' & 'the feminine'