Kamala beach is one of the best in Phuket. Relatively clean, and also safely swimmable in all seasons. Its the only beach in Phuket with a boardwalk and also including a selection of thai/international restaurants right on the beach boardwalk.
Kamala has a bit of a Thai Villlage atmosphere/vibe, but it is rapidly becoming the epicenter of newly built 5 star hotels on the island. Several 5 star hotel/resorts/condos are being built there right now.
There is currently a Big C supermarket and a plethora of cafe, restaurants, and pubs across the town.
Kamala is also very accessible to most of the other popular places in phuket. It is only 15 minutes drive to Patong, 10 minutes to Surin beach, 15 minutes to Bangtao, and 50 minutes to the airport.
The roads between kamala/surin and kamala/patong are currently being widened from two to four lanes. This will greatly increase already good accessibility.
Unlike bangtao or rawai, everything in kamala is within walking distance, so no need for a car or even a motorbike.
Seems to tick all the boxes of the OP.