Are weekend quests better than doing quests everyday? I hate the grind but I need to save a LOT of sP, so which is the better strategy?

Whichever weekend quest is selected to give increased prizes gives more than it does the rest of the week. The others just give normal prizes at weekends.

If you want to save a lot of sP you need to do all your quests every day of the week and regard the special weekend quest as a bonus.

yeah I was afraid of that.

while the "best" way to make a lot of sP is to do all quests every day, if you can't sustain that or it just isn't fun for you work out other ways.

Perhaps choose a combination of questing, games, restocking, etc.

Pick 3 or 4 questers to do everyday, plus the weekend quests, for example. Then toss in a few games to do daily. Choose one or two shops to learn really well and restock regularly.

Experiment a little, find things you really like and work at maximizing the profits you can make doing stuff you enjoy with as little grinding as possible of stuff you don't like.

If you're wanting a little motivation to grind through more quests, I find I get the morty cards a decent bit. Usually minimum once every other day and occasionally twice a day after I've done all of the quests. They're worth 1.6m each, which seriously adds up. Since that's your goal I think keeping those in mind helps. You could just do the quests until you get one every day, sometimes it's a few quests in sometimes you don't get one.

For me all combined

I get you, questing is so mindnumbingly boring To me, grinding trough my quests is a lot more doable if I put on a podcast or a audiobook while doing all that mindless clicking.

I find doing shinwas quests first to be helpful. Sometimes the prizes from a quest giver she has you visit are decent enough that you want to finish the set. Also Sometimes you get boosters from shinwa which you can keep or sell for constant tidy profits.