Importance of Amplifier versus Preamp?

Pre-amps are far more important, can make a so-so amp sound
good, best amp in the world will only sound as good as the signal from pre-amp.

I like to have a great amplifier with a good preamplifier with same brand and generation.
The most important to remember that the goal is to increase your enjoyment of music. To me, I'm listening through a component that is going to make me happy, relaxing, and just settling into the music not the equipment.

IMHO, the preamp is more important, BUT the amplifier/speaker interface is more critical. Once you get the amp and speaker match correct, a fantastic preamp will make it even better.

My opinion is that a general purpose answer can't be defined. It depends on the specific components that are being considered, and also on how synergistically they match up with the speakers, the source components, and each other.

I would emphasize, though, that the amplifier/speaker matchup is one of the most important considerations.

Regards,
-- Al