Honestly I am so over this 18-140mm kit lens I've been using, it is actually driving me crazy. I just spent the entire morning looking through my shots from a hiking trip last weekend and almost every single one is soft once you look at the corners and it's making me so anxious because I have a huge trip to Japan coming up in less than three weeks. I spent all this money on a Nikon D7500 thinking I was gonna get these crisp professional looking photos but everything looks kind of muddy and flat. I'm actually starting to regret getting into photography if I'm just gonna be disappointed every time I upload my SD card...

I need something that is actually sharp, like noticeably sharp even to someone who isn't a pro. I mainly do street stuff and landscapes when I travel so I need a decent range but I'm willing to sacrifice the long zoom if it means the image quality is actually there. My budget is sitting right around $600 or $700 and I've been scouring forums but everyone says something different and it's just making me more confused and stressed out. I'm looking at maybe the Sigma 17-50mm f/2.8 but some people say it has autofocus issues and I really can't deal with more technical problems right now. I just want one reliable lens that I can keep on the camera for 90% of the time while I'm walking around Tokyo and Kyoto.

Is there a specific Nikon or third party lens that you guys swear by for travel that won't weigh a ton but still gives that wow factor? I'm really worried about wasting more money on glass that doesn't perform. What should I be looking for if I want to finally see what my camera is actually capable of?