Mastodon's light theme (especially with advanced interface disabled) is better than twitter's light theme, because the actual background color of the body is a light gray that's imho easier on eyes than full white but more importantly is slightly blue (#EFF3F5) so it still has personality and feels alive, while as Twitter's light theme uses almost entirely full blinding bright white and monochrome grays.

Which is weird, because Twitter's dim dark theme is very saturated and feels nice to me.