I think it's the article that's confused, or being a bit careless with the details. Like you say, Deflate is based on LZ77, and I think it's not just for paten

I think it's the article that's confused, or being a bit careless with the details. Like you say, Deflate is based on LZ77, and I think it's not just for patent reasons but because it's a nice algorithm. More modern algorithms like LZMA is also LZ77 based.