There are mods that add monsters, crafting, building, magic.. mods are a good thing'

It's totally worth the replay. Sooo much new content since then

I started a completely new game for my Mistlands run and I saw there was some new stuff sprinkled in the old biomes.

Il just wait til the biomes are all out. And maby even when the game is finished. Im sure its great now, but ive already played 350hrs of the earliest version. When all the biomes are out, there will Definitely be enough new stuff to tinker with. So... a couple more years? :D

It's definitely worth it to replay. but if you're worried about it being repetitive try a different playstyle, such as a different weapon or food combo
EDIT- autocorrect got the best of me

There's a couple new things in old biomes as well. One troll-tier enemy, one new dungeon type (complete with new enemies), one new dangerous overworld feature with enemies, scattered through the original biomes.

The new biome is both liked and loathed, but is challenging. So hard to say really, the game is what it is.

If you're looking for "lots more content" and "more depth," you'll probably be a bit disappointed, but there have been a number of improvements in other areas, like optimization and bugfixes. Despite the aforementioned disappointment, I'd say it's probably worth replaying, especially if you've got a group to play with. Don't count on that "fresh" feeling, though. Valheim Virginity can't be taken back.