It's totally normal to look out for Wi-Fi connections when you're out in public. Not only is Wi-Fi generally faster than using data, it also saves you using up all of your own precious megabytes. What you don't want to do is waste time signing in to weak networks, only to realize you can't even use the internet properly on them. What's worse is that some of them make you go through a lengthy sign up process!
If you're in an area with patchy Wi-Fi connections, there's a way to filter them out so you can jump onto a good one, or simply keep using your data. The way to do this is by visiting Settings > Cellular and then switching 'Wi-Fi Assist' on. You'll never have to waste your time on a terrible connection again.