It's had a huge negative impact. Pirating cuts into the profits of manga creators and publishers, making it harder for them to keep creating and distributing new content.
The best way to avoid pirating manga is to buy or subscribe to legal platforms. That way, you can enjoy the content while also supporting the creators and the industry.
Well, some popular manga websites include Viz Media and MangaFox. Viz Media offers officially licensed content, while MangaFox has a large collection but be aware of the legality of some uploads. It's always best to support official sources when possible.
Websites like KissManga and MangaFox are often used. They offer a large collection and are user-friendly. However, be aware of potential ads and the legality of some content.