Honestly, I was getting pretty tired by this game around hours 8-15 as well. It felt like it never picked up steam. But then suddenly shit started happening, dungeons got more interesting, mechanics opened up.
I was even getting through a phase of buyers remorse - now I can't wait to continue onwards.
Not saying this will happen for you - DQ is definitely an acquired taste for me, and I always had the problem of abandoning them before they really got interesting. I'm definitely more a battle mechanics > everything else person in JRPGs, and this game is the slowest burn in a series that always started off simple and easy going.
Just had my first boss battle where I died three times in a row, carefully rearranged the items everyone was carrying, discovering new gear in the preceding dungeon, remembering that I can make a quick save just before the boss room, and then having a battle with only one character still standing.
And regular encounters started getting more interesting as well, with enemies being able to dazzle you for multiple turns, doing brutal fire attacks, or suiciding into your party.
I mean, your team unlocks only a handful of very basic abilities for the first 20 hours. Then it suddenly opens up this huge selection of classes.
If you are into these games for interesting mechanics like I am, the first 15 to 20 hours can feel like quite a tease, but it feels incredibly rewarding after that.
I honestly can't remember the last time a game did this to me. I'm so used to games offering me all their mechanics right from the start. But I probably wouldn't have kept at it if I wasn't aware of how much content the game has to offer after a certain point.