Regarding the current state of casters.

[Yeol]

How I see it:
Average group compositions can clear Savage.
Meta group composition can clear Savage.

They both can clear Savage. A clear is a win.

The only difference is how fast each group is clearing. This matters to some people because they enjoy speed kills. It doesn't matter to others because they are happy with just clearing content.

1. Are you all ok with this? Why?

I'm totally okay with it. Just because your static is following meta, it doesn't mean that they can do speed kills. You need very good players to do that.

2. I tried to elaborate my answer to this question with my lengthy text, but how do you all think we got to this point in job balance?

Like you said, some jobs are good to have during the first weeks then they get benched during the last ones. What they offered is not needed anymore. Only groups doing this though are ones that are going for speed kills. Aka, they level multiple jobs, and gear both in order to use one for progression and the other for speed kills.
To me, this doesn't sound very bad because both jobs were used.

3. Do you have any suggestions to improve this situation?

I can't say much about this personally but ... Making all jobs equal is a bad idea.
Some jobs are harder to play than others. If they do the same dps as the easy job, why bother playing the hard one?

- SAM is easy with high dps, but it gives no party buffs.
- MNK and NIN are not as easy as SAM and deal less damage, but they make up for it with party buffs.
To me, this is balanced. But what I think it balanced and what other players think is balanced might be completely different.

The only problem with having meta this is that there are some players that think meta is a must. Which is completely wrong.
I'll quote myself:

Just because your static is following meta, it doesn't mean that they can do speed kills. You need very good players to do that.

If your group is meta but failing to do speed kills, why bother with it.