colonialism is always a brutal affair and other groups have treated Taiwan poorly as well. But this idea that Japanese colonialism was good for Taiwan is downright perverse

It undoubtedly was good for Taiwan on a collective basis. Sure, bad things happened, but overall, people got better education, better healthcare, access to small modern luxuries, technology, etc. Would Taiwan be better off today without the Japanese occupation? Hell no.

This notion that 'because there was rape and murder there was no collective benefit to society' is what's perverse. It's just as one sided as the 'The Japanese were just bringing us into the modern world!' video. The reality is, the Japanese were self-interested, and they viewed their self-interest as roughly coinciding with the self-interest of the Taiwanese people, so they gave the Taiwanese people some of what benefited them.

However, their self-interest did not wholly coincide with that of the Taiwanese, so they did some pretty nasty stuff that went against the self-interest of the Taiwanese, too.

However, as it turns out, they gave Taiwan things of lasting/exponentially compounding value -- better infrastructure and knowledge/skills. They inflicted upon Taiwan evils of generally declining detriment; rape and murder. The rape and murder hurts less over time. The value of the leg up in tech and education helps more over time.