It totally depends on your niche. In B2C niches I would do 3k words max because people have low attention spans nowadays. Many people are victims of excessive dopamine fixing (junk food, high fat and sugar intake, p0rn, TikTok, mobile games, gaming, Netflix etc.). In B2B niches, 10k words are totally fine if you're providing value, and it's interesting to read. But also in B2B, I wouldn't focus on the amounts of words. Just try to say everything you want to say as concise as possible.
Sincerely,
The Data Scientist