I agree with Jules. I like the 24-teams format.
The old one was quite boring and exhausting for the players, to be honest. We had 3 pool stage games, then playoffs for places 2-3, quarterfinals, semifinals and finals. That's 7 games in 9-10 days!
In addition, I think, volleyball gets more recognition in Europe with the new format. The games are broadcasted in many countries.
With the old format, we wouldn't probably have Sweden and France in Eurovolley 2021.