Its a personal preference, you should try both. That said, I strongly prefer clipless.

To me, its much better to have equipment suited for each task. Shoes for riding, and lightweight shoes for walking and or hiking. 200g or less for a dedicated pair of walking shoes is worth it to me.

Clipless is soooo much better (to me).

1)I feel so much more stable. Rain, downhills, rough roads or gravel, you know your feet aren't going anywhere unless you want to. Even more true when you're tired. Unclipping is probably about 99% as fast as taking your foot off the pedal once you are used to it.

2)If you get a decent pair of shoes, the soles will be much, much better than a pair of sneakers and also better ventilated. Anyone who complains about "hot spots" doesn't have the right shoe.

3) You can put on cycling booties/toes if its cold and the same if its wet. Hard/impossible to do with sneakers

4)Slightly more efficient pedal stroke. (though people will argue that, but smoother is going to be more effecient imo, and also better for the body)

SPD style are good for options and price. For functionality I like the Eggbeater platforms, but those are more expensive and more difficult to source if something goes wrong (though they are pretty much bullet proof, especially just for touring).