I really started to enjoy Workspaces and the vertical tabs in Arc (and the browser UI design) but Arc’s aggressive tab sleeping and unreliable tab syncing finally became too annoying.
I was losing page state because of tab sleeping and the tab sync process usually wiped away about half of my tabs.
Now I’m trying Vivaldi, which has Workspaces, vertical tabs, and isn’t as aggressive about sleeping tabs. It also doesn’t force me to sync tabs.