The question is always whether leather ones are worth the extra over anything synthetic, and yes, nearly always, because the difference shows up on your feet after about three wears, not three years.
A well made leather sandal tells you what it is before you've even walked in it. The leather should feel slightly stiff out of the box and then soften properly, moulding to your foot rather than just going saggy. Cheap versions do the opposite: they feel soft and giving on day one because they're not really leather through, just a thin coating over something that cracks at the crease by August. Check where the straps meet the sole. On a good pair that join is stitched or properly riveted, not just glued, and you can usually tell by giving the strap a firm tug, which I realise looks odd to do in a shop but has saved me more than once. The footbed matters more than people expect from something so simple. A leather lined insole takes the shape of your foot over a summer and stays that shape, which sounds like a small thing until you've worn a pair with a flat synthetic insole that never settles and leaves you adjusting your stride all day. Hardware is the other tell. Buckles that are a dull, slightly heavy metal tend to survive, where thin shiny ones go tarnished and bent by the second summer.
They pair with almost everything you'd actually wear in warm weather, which is the point of them. A plain linen dress, wide leg trousers rolled at the ankle, denim shorts that have gone a bit soft from washing, they all look better with a leather sandal than with anything that looks like it came out of a multipack. The trick is letting the sandal be the only leather thing happening, so a plain strappy style works harder than a heavily buckled one if you're already carrying a bag with its own hardware going on. For colour, I've come round to tan and a proper mid brown over black, because they age rather than just fade, and they go with warm and cool colours alike without you thinking about it. A soft, worn in looking leather, even when new, outlasts anything with a glossy finish, which scuffs the first time it meets a pavement edge and never looks right again.
They go into a bag crushed, get rained on at a barbecue, spend a week forgotten under a sun lounger, and a decent pair comes back from all of that looking better for it, not worse.
The real pleasure is a strap worn in exactly to the shape of your foot, so slipping them on stops being a decision and just happens.