Summoning Japan is still kinda power fantasy, but it’s much more focused on the world itself rather than any specific characters. It’s also consistently REALLY good. It’s still running, but there’s quite a bit already out before you have to wait.

Manifest Fantasy is a similar premise to GATE but much better, though is still an early Work In Progress; it too is REALLY good so far (there’s five chapters out so far AFAIK)

Then there’s Summoning America, written by the translators of Summoning Japan. I haven’t read it but I’ve heard good things about it.