Yes they do. Investment bankers are traveling salesmen. Specifically, they’re selling money to companies.
Say a company wants to get money to build a factory or hire more workers or whatever. It can get that money by issuing stock or bonds. “Issuing bonds” just means “borrowing money from strangers.” “Issuing stock” is more existentially complicated, but “giving people partial ownership of your company in exchange for cash” is good enough.
Issuing stocks or bonds requires finding someone to buy them, and most companies aren’t good at selling stocks and bonds, so they hire investment bankers as middlemen to help them find people looking to invest money.