Busses (or plugins)?

Since I don’t want to mix up different sunjects, I open this post here.
I lately used a bus for the first time in a mastering. A simple one with a compressor.
Now the question is: is it better to use busses WITH plugins in each or to use plugins in each track of the song?
I try to be clearer. Put the case I have a song with 4 tracks. In each track I have a reverb which different setup.
So I have 4 plugins with 4 different setup.
If I put busses in the song instead plugins, I have to add 4 busses, one for each track, each with a reverb with its own setup, right?
I thought that if I only have one bus with a reverb, it’s not possible to get 4 different setups, one for each track.
Which of the two way is better? I guess having a plugin for each track is more process/disk/ram saving than having a bus with a plugin for each track, isn’t it?
Thank you

Not quite. You only add one bus, with the reverb plugin on it. Then use aux-sends from the tracks to that bus.

Especially with reverbs, prefer a single reverb for all sources. That will sound a lot more consistent (all in the same space).

The reverb on the bus should be 100% wet, and you control the amount of reverb using the aux-send levels on each track.