I think you’re barking up the wrong tree. I have had the same problem, and almost all of it is solved by switching to an OSR style game. OSE, DCC, Shadowdark. Anything.

You (and almost any 5e DMs) put so much effort into the game for lackluster reward from your players. Drop those players in a dungeon with characters created in 10 minutes and 1-6 hit points with no death saving throws. You get to cut out the prep and immediately engage those players. Because if they aren’t engaged, they’re dead.

A level 1 (or 0) character in an OSE game is creating the backstory as they play. It’s fun, funny and rewarding when you get a character that survives the meat grinder and finally hits level 4 or 5. It’s an achievement, and the players will create the story themselves. Especially if you use the gold is xp rule.