I play on a dedicated server I hosted for my friends and myself.
Today I decided to uninstall because of the desync/lag issue. After 4 hours of gameplay in the server, my friend logged in and together we found out I was stuck, staring into an unfinished floor.
In my client,I had built a huge castle for the last 4 hours. For the server, I had been staring at the floor for hours.
I love the game, I've got my money's worth (100+ hours). But it is at the moment impossible to enjoy the game *edit* due to the size of our world *edit*. This instance was the latest, but we've had our fair share of flying boats, disappearing buildings, disappearing items, etc, all due to not knowing we are unsynced to the server. I would rather get a hard disconnect, and have to log in, than keep playing unsynced.
I'll be back, but for now, my soul rests in Valhalla.
Source: https://www.reddit.com/r/valheim/comments/m0y1ab/i_uninstalled_today/