I gotta confess, I had that same feeling at one point. Especially since at early 2.4, my mains were Summoner and Dragoon.

I am curious. The OP has stated a dislike for Summoner, But do you dislike it because of that fear of being left behind, or do you dislike the way it plays as well. If it is the later, then yeah, change classes, without consideration for your book. It's a game, you shouldn't be playing something you don't enjoy.

If you like the class, but dislike it's perceived weakness, then I'm not sure, maybe try to ignore the future. Currently, the issues with summoner are a result of the Current endgame exposing it's weakness, it will not always be as such. If people are currently telling you to switch, then pose the arguments stated in this thread and ask your questions of the people telling you to quit being a summoner. If you can't, or they manage to sway you, then find another class you enjoy to play.

In short, just do what you think is best to have the most fun.