>lightweight, nimble and agile
>breathable
>inexpensive
>durable (assuming we're not talking 5$ walmart sandals, in which case, what else did you expect?)
>superior adjustability (your foot swells after a long break from hiking? Just readjust the strap. Want to add a pair of wool socks? Go ahead. No worrying about sizes and tightness like with shoes and boots.)
>easy maintenance (no leather treatment or waterproof membrane cremes or bullshit.)
>more natural form (most don't have a prominent (((heel))) like other footwear that was a holdover from poorfags trying to emulate richfags)

Common complaints and why they're bullshit:
>but muh small pebbles/debris will get stuck in there!
Toughen up, kiddo. None of that shit never hurt anyone. If you're worried about cactus needles, then stop wading through cactuses, dumbass.
>but muh water! It'll get wet when I go through a creek!
Toughen up, kiddo. It's water. And unlike if you were to get a shoe wet, you're not gonna get trench foot in sandals. No more worrying about carrying an extra pair of socks, either.
>but muh cold!
Bullshit. Wim Hof climbed Kilimanjaro in sandals. If you're weak you could try wool socks and additionally goretex oversocks and keep most of the benefits described above.
>but muh hippy! Muh bad fashion!
No one cares.
>but muh ticks and bugs!
Toughen up.
>but muh ankle support!
There are over a dozen different tendons, muscles and ligaments holding your ankles together. Wow, it's almost like humans came factory-issue with plenty of ankle support.

About the only time where sandals are not OK is in extreme cold, i.e. in taiga climes in January. So this fringe climate aside, what's your excuse for not wearing sandles for the majority of your goings /out/?