is it possible to make plugin for handheld torches? You would think that Mojang would have done something like that by now.
I doubt it. The server can’t control lighting on the client after the client sees the chunk, except by placing blocks automatically.
I think the reason they haven’t is because recalculating light for every block a player moves would be quite slow, especially when multiple players are holding torches at once.
But if you want it in vanilla, there’s a post on the Minecraft feedback site where you can vote for it: https://feedback.minecraft.net/hc/en-us/community/posts/360010973971-Torch
As requested. It basically will spawn a torch on the ground behind you that disappears after a few ticks. It can not be mined or picked up and only spawns while holding a torch.