If you're returning and behind on gear, the season server is the fastest equalizer in the game. You grind Tuvala gear to a high level for free, then graduate it into the regular economy. It removes the "I'm years behind, I'd have to whale" problem entirely.

Verdict: If you're below around 600 gear score and returning, do a season character before touching your main. It's the highest-value time you can spend.

The catch: season gear has rules (no marketplace, specific enhancement). Follow the season guide, not your nostalgia. The point is the graduation, not the journey.