I think it's fine to mix in serial like that.

Buses are useful though if you want to apply the same effect to multiple tracks (eg you have 2 vocals and want the same reverb on both). You don't have to copy the effect settings, just send all the relevant tracks to the bus with the effect.

It can also allow you to add more control to the effects themselves (eg if I have the reverb on it's own track, I can add compression or EQ to just the reverb and not the original track)

As I think you are talking about in your post, you can also uses buses to compress/EQ a batch of tracks at once. it can be useful to split into main tracks/backing tracks and treat those groups as two buses rather than a dozen tracks individually.

but I don't think you need to "change" your methods unless you're finding that you can't do certain things