I was 15 when Blade came out, and the primary reason I didn't see it in theaters at the time was because it was advertised as more of a horror movie and rated R. So my parents didn't let me see it back then, and I actually haven't seen it yet either since it's just one of those movies I keep forgetting about. Also IIRC, the marketing around the movie wasn't great either, and made it look less than great. It didn't really catch my interest back then either. Although Spider-Man TAS was airing back then as well and had Blade in a few episodes, I never made the connection it was the same character.
I agree that X-Men is what fueled the revolution, and Spider-Man just made it more popular. For me X-Men was one of the first movies I got to see in a theater without one of my parents, and I'd also add that it really helped that X-Men TAS came before it. The TAS introduced me to the characters, so when the movie's marketing started, it became a movie that I really wanted to see.
Likewise for Spider-Man TAS, which introduced the character for me and got me pumped to see the movie. I think if Blade had been more prominent in the series, it might've helped more people been aware of the character. For me I pretty much didn't know who he was at the time, so I had little interest in the movie.
I'd be willing to bet most of the average movie-going audience had no idea who Blade was when that movie came out, and probably considered it as more of a horror movie, because I certainly did. Plus the movie's rating probably didn't help its box office. IMO, part of X-Men's success was its PG-13 rating, plus the fact it already had a fanbase from the TAS, and thus way more people knew about it, including parents of the millennials who grew up on that show.
