I prefer a sub. By making people pay to play the game you get rid of many toxic people who will keep playing f2p. Having a sub acts as a filter of players and WoW playerbase is already too toxic for that amount to increase.
Besides, 13€ a month is not a huge amount of money for someone who works. WoW can be one of the cheapest hobbies thinking about the number of hours played. I wouldn't think it's outdated when there are many sub models for services like Netflix, Apple music, Amazon prime...etc. I would argue as another user said that you only get one game with the sub (well two if we count classic) compared to other thinks like Netflix in which you get a huge catalogue of movies and tv series or compared to a game pass, but that's it. I wouldn't call it outdated really and I prefer it to the f2p model. We would have to pay for every bit of content we would want to play, it would be even more pricy that way.