A large portion of the shine you see from professional ceramic coating applications IS paint correction before application. The industry is changing from the high end only to a certain amount of ceramic product being in various levels of diy products. Lifespan of product is a big difference.
A true ceramic seals the paint from breathing. This seems to be acceptable on new car forums where cars have thin *ss paint, but on the SPI forums where thick paint is freshly sprayed & can still offgas for years, it's an absolute no no. Paint forum guys use detailer spray & or carnuba based waxes only. Products labeled paint shop safe, such as most correction polishes, meguiars #7 showcarglaze etc, give a good true shine improvement, but don't seal paint or leave anything wax & grease paint remover can't clean off for new paint. Ceramics, like the old liquid glass can potentially be a painter's mightmare. Good carnuba can last for up to a few months.