For chiefly functional items like raincoats, the styles haven’t changed much in 70 years. So absent a bit of new technology (i.e. the Nau crowd), your best bet is a brand that’s been building up cred for a few decades…or one of their more recent collabs.
Someone else got to Mackintosh first, so the folks at A.P.C. turned to a Canadian slicker marque called K-Way, resulting in this puffy anorak. Not a bad idea for summer rains…especially if you run across a storm that makes you lose your faith in waxed cotton.