I thought I was some. He looked so much better older
Exactly, I don't read the novel, but I don't think the God had any reason to make him younger.
My guess would be that humans still have the same lifespans and the God wanted that the funnel he would pour magic through would have as much time as possible alive, but if that's the case why wouldn't he just make him an elf or some other long lived race it's the real question
Maybe it's just God's whim. Hopefully he will become older as time passes, I need more older man getting isekaid（￣へ￣）
I think they're often transmigrated younger to give them more allowance for not knowing how things work in the world. If they're an adult, it's much stranger to not know common knowledge. In the isekai I read where they stay an adult, the plot style is generally quite different, less about adventure and more about stability.
Kinda disappointed when he became younger, he looks more handsome before. But still interesting tho.