It’s funny to me when people wonder what else there is to do if not quest….as if the game was somehow unplayable for all those years before trader quests were added.
That being said the solution really should be a selectable option. Reducing quest rewards, lengthening the quest chain for the next tier, and limiting quests per day/week are great for slowing down speed runners but then everyone else playing at a normal pace may feel like it takes too long to get to decent rewards but then those rewards aren’t worth it compared to what I can already craft, etc.
Let the speedsters complain that they get endgame stuff by the end of the first week but let’s not “balance” the game to their pace unless it is simply selectable options for number of quests allowed per day or week, number of quests needed to complete a tier, and rewards options like cash only or loot and cash.
It's not 'what to do if not quest?', it's 'quests are so good, why do anything else?'. And sure, this debate about 'just limit yourself to totally suboptimal playstyles, you'll have more fun' has meandered around on these boards for a while, but I don't feel it's a strong argument. There's a gap between 'minmaxers will find the path that's very slightly better than the others and pursue that exclusively' and 'doing one thing is so much better than all the others it seems like perverse game play to ignore it'.
I'm not asking for perfect balance, I'm asking for BETTER balance. Currently the divide between questing and not questing is vast, in terms of rewards. Good game design does require that the player makes difficult, meaningful choices. When one choice is always better, in every situation, you've removed player agency.
It's not some weird outlier 'speedrunners' breaking what would otherwise be a balanced system, either.
When Tier 2 quests give out Q5 iron tools and weapons you're invariably going to have a situation where quest rewards totally outstrip what you can do for yourself, whether by buying, looting or crafting.
Q6 steel weapons at Tier 4 doesn't help either, but you do at least have to do a significant number of quests for that.
The other major factor is that there's almost zero opportunity cost to doing quests. 'The rewards aren't worth it' never applies because the rewards are just a freebie on top of normal loot and exp for that POI. Sure if quest POIs had an empty final loot room or something, then we might get the hard choices back (do I loot where I want or do what the trader wants?) but currently the small price of having to loot a specific POI, rather than chosing a target freely, is a tiny price to pay compared to the quality of extra rewards on offer.