Im just building off a thought I had but I believe that every office business should have some unique active or passive ability that It presents to the players to use bar head office jobs as they serve unique functions. More than just easy cash, office jobs should help players set up how they want to expand their businesses in a specific sector. For example At the moment, you can have lawyers provide a reduction in taxes from all businesses in a specific area. For Web agencies you can have a one time boost to the marketing of a business. for Graphic design agencies, they provide a flat small improvement to all the businesses in a specific district. effects like these and more can really help with subsequent business openings as the buffs from the office jobs help create more favorable condition for the player to invest more in that district, while other office jobs help with opening businesses in new districts.
Add a reason for the player to go into other office businesses early game.
I have never once in my 200 hours of play time walked into an office business that is not mine. I think this should be changed, make it similar to the player needing to use other characters gyms, supermarkets and fast food stores.
Have it so that to get a lease on a building for example, the player must use legal advice from a law firm. Have this similar to recruitment where it takes time to sign the lease for the lawyer to look over the documents, maybe even have it so lawyers are required to form a business in the rented building as it is IRL.
Graphic design and web design could be to generate ads that you then run through the advertising companies. Again like recruitment , you pay money for a certain type of ad, and it takes time to get results.
I think it could be really cool if all these graphic design places had a purpose and could create cooler looking business signs for your businesses. I know we can copy in our own images into file folders outside of the game but this method would not only be easier for players but would also give more of a purpose to these graphic businesses.