Naver Webtoon, for one, has rolled out an in-house tool named Toon Radar that embeds invisible watermarks in each chapter. When a pirated copy turns up online, the watermark allows the company to trace it back to the specific account that downloaded it.
I’m cool with paying for actual files that I can store on my own machine. Fuck the DRM and subscriptions though. Also don’t charge the same price as a physical book. I bought the entire Walking Dead comic series from Humble Bundle for $18 back in 2020. It was all the .cbz/.cbr files. I do like to support artists and that was a fair price. Very rarely are those requirements met for me though.