I feel like Equestria Girls was bound to happen at some point in the franchise, and I don't see it as a bad thing. A lot of the gripes I see people have online are that stuff like this is a cash grab or whatever, and even if they are, it's because it works. People love the MLP characters, so make them more relatable as teenagers in high school. but I also think they did it in a more interesting way and expanded on it greatly, like it being a different dimension was a good choice IMO, while also doing creative parallels like Twilight coming from Canterlot in the pony world and Sci-Twi coming from a different school in the human world and both meeting and becoming friends with the same group of ponies/people lol. i also feel like it's a way to have more relaxed and realistic content from these characters (even if magic is still a thing), it's still a bit more grounded because they're having more human experiences