Are full casting progression and high tier characters overrated?

[Quertus]

. But a fighter can't make a time altered dimension where they full rest between encounters

Make? No. But utilize? Yes. If my Artificer created all the gear that the party uses, then contributes nothing during play, well, creation is overrated.

That having been said, utilizing a full rest between encounters (let alone chain gating solars) breaks the fundamental resource management basis of the game. If you're breaking the game, there's little point in discussing balance.