A Google Business Profile is not a social page you post on when you remember. It is the card Google shows when someone searches your trade plus your town. If that card is wrong, the site never gets a chance.
The category is too vague — or there are twelve of them
“Company” or “establishment” tells Google nothing. An optician is an optician. A driving school is a driving school. One precise primary category beats a pile of extras you hoped would cover every keyword.
Secondary categories are useful when they are true (for example a garage that also sells tyres). They are noise when you add “restaurant” because you have a coffee machine.
Hours, address and phone that do not match the door
Saturday morning closed on Maps while the lights are on is how you lose the person who drove over. A phone that rings in an empty office is worse. Put the number you actually answer.
Do not use a PO box or a town 20 km away because it “sounds nicer”. Google checks distance. Customers check the pavement.
Stock photos, no website, or a website that 404s
Cover photos of generic laptops tell people you are not really there. Façade, counter, team, the actual street. Then put a real URL in the website field — one that loads on a phone.
If you do not have a site yet, say so and still keep the profile honest. Then get a page up. Maps wants somewhere to send the curious.