thats still going to be uncomfortable:
2019 Wanda: I'm here to take vision, he dies in this timeline
Past Wanda: NO. i'll fight for him and protect him. give me that chance.
2019 Wanda: no. trust me, he dies
Past Wanda: now that we know, we can take extra measure to prevent that from happening. \\
etc etc
can you imagine somebody from the future telling captain america "you guys fail, so i'm going to take your "... you think cap would just shrug and say "oh ok we're gonna lose anyway, no biggie then"
unless you abandon the philosophy of giving a about the other timelines (in which case no need returning the stones). also, if you dont return the stones, you actually save all those timelines from the snap happening. whatever, there's going to be all kinds of goofiness when time travel enters the equation, sorta just have to let it go i guess